From Server to Desktop: Capital and Institutional Planning for Client/Server Technology.

Science.gov (United States)

Mullig, Richard M.; Frey, Keith W.

1994-01-01

Beginning with a request for an enhanced system for decision/strategic planning support, the University of Chicago's biological sciences division has developed a range of administrative client/server tools, instituted a capital replacement plan for desktop technology, and created a planning and staffing approach enabling rapid introduction of new…

Aplikasi Billing Client/Server Dengan Mengunakan Microsoft Visual Basic 6.0

OpenAIRE

Sinukaban, Eva Solida

2010-01-01

Kajian ini bertujuan untuk membangun Billing Server yang gratis dalam jaringan Local dengan media transmisi berupa kabel UTP atau Wifi, Jaringan LAN yang dibangun ini merupakan jaringan client server yang memiliki server dengan sistem operasi yang dipakai adalah windows XP Service Pack 2. Tujuan pembuatan Aplikasi Billing Server ini adalah untuk dapat melakukan sharing data dan komunikasi antar komputer sehingga komputer-komputer tersebut dapat dimanfaatkan seoptimal mungkin baik dari sisi Se...

Client/server approach to image capturing

Science.gov (United States)

Tuijn, Chris; Stokes, Earle

1998-01-01

The diversity of the digital image capturing devices on the market today is quite astonishing and ranges from low-cost CCD scanners to digital cameras (for both action and stand-still scenes), mid-end CCD scanners for desktop publishing and pre- press applications and high-end CCD flatbed scanners and drum- scanners with photo multiplier technology. Each device and market segment has its own specific needs which explains the diversity of the associated scanner applications. What all those applications have in common is the need to communicate with a particular device to import the digital images; after the import, additional image processing might be needed as well as color management operations. Although the specific requirements for all of these applications might differ considerably, a number of image capturing and color management facilities as well as other services are needed which can be shared. In this paper, we propose a client/server architecture for scanning and image editing applications which can be used as a common component for all these applications. One of the principal components of the scan server is the input capturing module. The specification of the input jobs is based on a generic input device model. Through this model we make abstraction of the specific scanner parameters and define the scan job definitions by a number of absolute parameters. As a result, scan job definitions will be less dependent on a particular scanner and have a more universal meaning. In this context, we also elaborate on the interaction of the generic parameters and the color characterization (i.e., the ICC profile). Other topics that are covered are the scheduling and parallel processing capabilities of the server, the image processing facilities, the interaction with the ICC engine, the communication facilities (both in-memory and over the network) and the different client architectures (stand-alone applications, TWAIN servers, plug-ins, OLE or Apple-event driven

Location Privacy Techniques in Client-Server Architectures

DEFF Research Database (Denmark)

Jensen, Christian Søndergaard; Lu, Hua; Yiu, Man Lung

2009-01-01

A typical location-based service returns nearby points of interest in response to a user location. As such services are becoming increasingly available and popular, location privacy emerges as an important issue. In a system that does not offer location privacy, users must disclose their exact...... locations in order to receive the desired services. We view location privacy as an enabling technology that may lead to increased use of location-based services. In this chapter, we consider location privacy techniques that work in traditional client-server architectures without any trusted components other....... Third, their effectiveness is independent of the distribution of other users, unlike the k-anonymity approach. The chapter characterizes the privacy models assumed by existing techniques and categorizes these according to their approach. The techniques are then covered in turn according...

A Java based environment to control and monitor distributed processing systems

International Nuclear Information System (INIS)

Legrand, I.C.

1997-01-01

Distributed processing systems are considered to solve the challenging requirements of triggering and data acquisition systems for future HEP experiments. The aim of this work is to present a software environment to control and monitor large scale parallel processing systems based on a distributed client-server approach developed in Java. One server task may control several processing nodes, switching elements or controllers for different sub-systems. Servers are designed as multi-thread applications for efficient communications with other objects. Servers communicate between themselves by using Remote Method Invocation (RMI) in a peer-to-peer mechanism. This distributed server layer has to provide a dynamic and transparent access from any client to all the resources in the system. The graphical user interface programs, which are platform independent, may be transferred to any client via the http protocol. In this scheme the control and monitor tasks are distributed among servers and network controls the flow of information among servers and clients providing a flexible mechanism for monitoring and controlling large heterogenous distributed systems. (author)

Development of a Client-Server Chat Application

OpenAIRE

Malmberg, Lasse

2017-01-01

The goal of the Bachelor’s thesis was to develop a simple client-server chat application. The focus was on the development process and the underlying technologies that were utilized in the development of the chat application. The chat application was developed with the C++ programming language and the SDL software development library. The development environment consisted primarily of command-line operated tools. The thesis resulted in a functional chat application. The program is a d...

A RAD approach to client/server system development

International Nuclear Information System (INIS)

Brule, M.; Fair, W.; Jiang, J.; Sanvido, R.

1995-01-01

The capability, richness, and leverage of inexpensive commercial operating systems, off-the-shelf applications, and powerful developing tools have made building feature-rich client/server systems possible in rapid time and at low cost--ushering in a new level of systems integration not before possible. The authors achieve rapid application development (RAD) by using a flexible and extendible client/service integration framework. The framework provides the means to integrate in-house and third-party software applications with databases and expert-system knowledge bases and, where appropriate, provides communication links among the applications. The authors discuss the integration framework's capabilities, explain its underlying system architecture, and outline the methods and tools used to customize and integrate many diverse applications

Assessing Server Fault Tolerance and Disaster Recovery Implementation in Thin Client Architectures

National Research Council Canada - National Science Library

Slaydon, Samuel L

2007-01-01

This thesis will focus on assessing server fault tolerance and disaster recovery procedures for thin-clients being implemented in smart classrooms and computer laboratories aboard the Naval Postgraduate School campus...

A Server-Client-Based Graphical Development Environment for Physics Analyses (VISPA)

International Nuclear Information System (INIS)

Bretz, H-P; Erdmann, M; Fischer, R; Hinzmann, A; Klingebiel, D; Komm, M; Müller, G; Rieger, M; Steffens, J; Steggemann, J; Urban, M; Winchen, T

2012-01-01

The Visual Physics Analysis (VISPA) project provides a graphical development environment for data analysis. It addresses the typical development cycle of (re-)designing, executing, and verifying an analysis. We present the new server-client-based web application of the VISPA project to perform physics analyses via a standard internet browser. This enables individual scientists to work with a large variety of devices including touch screens, and teams of scientists to share, develop, and execute analyses on a server via the web interface.

Low-cost workbench client / server cores for remote experiments in electronics

OpenAIRE

José M. M. Ferreira; Americo Dias; Paulo Sousa; Zorica Nedic; Jan Machotka; Ozdemir Gol; Andrew Nafalski

2010-01-01

This paper offers an open-source solution to implement low-cost workbenches serving a wide range of remote experiments in electronics. The proposed solution comprises 1) a small (9,65 x 6,1 cm) Linux server board; 2) a server core supporting two TCP/IP communication channels, and general purpose I/O pin drivers to interface the remote experiment hardware; and 3) a client core based on a multi-tab user interface supporting text file management to exchange experiment scripts / status informatio...

A Client-Server System for Ubiquitous Video Service

Directory of Open Access Journals (Sweden)

Ronit Nossenson

2012-12-01

Full Text Available In this work we introduce a simple client-server system architecture and algorithms for ubiquitous live video and VOD service support. The main features of the system are: efficient usage of network resources, emphasis on user personalization, and ease of implementation. The system supports many continuous service requirements such as QoS provision, user mobility between networks and between different communication devices, and simultaneous usage of a device by a number of users.

TogoDoc server/client system: smart recommendation and efficient management of life science literature.

Directory of Open Access Journals (Sweden)

Wataru Iwasaki

Full Text Available In this paper, we describe a server/client literature management system specialized for the life science domain, the TogoDoc system (Togo, pronounced Toe-Go, is a romanization of a Japanese word for integration. The server and the client program cooperate closely over the Internet to provide life scientists with an effective literature recommendation service and efficient literature management. The content-based and personalized literature recommendation helps researchers to isolate interesting papers from the "tsunami" of literature, in which, on average, more than one biomedical paper is added to MEDLINE every minute. Because researchers these days need to cover updates of much wider topics to generate hypotheses using massive datasets obtained from public databases or omics experiments, the importance of having an effective literature recommendation service is rising. The automatic recommendation is based on the content of personal literature libraries of electronic PDF papers. The client program automatically analyzes these files, which are sometimes deeply buried in storage disks of researchers' personal computers. Just saving PDF papers to the designated folders makes the client program automatically analyze and retrieve metadata, rename file names, synchronize the data to the server, and receive the recommendation lists of newly published papers, thus accomplishing effortless literature management. In addition, the tag suggestion and associative search functions are provided for easy classification of and access to past papers (researchers who read many papers sometimes only vaguely remember or completely forget what they read in the past. The TogoDoc system is available for both Windows and Mac OS X and is free. The TogoDoc Client software is available at http://tdc.cb.k.u-tokyo.ac.jp/, and the TogoDoc server is available at https://docman.dbcls.jp/pubmed_recom.

TogoDoc server/client system: smart recommendation and efficient management of life science literature.

Science.gov (United States)

Iwasaki, Wataru; Yamamoto, Yasunori; Takagi, Toshihisa

2010-12-13

In this paper, we describe a server/client literature management system specialized for the life science domain, the TogoDoc system (Togo, pronounced Toe-Go, is a romanization of a Japanese word for integration). The server and the client program cooperate closely over the Internet to provide life scientists with an effective literature recommendation service and efficient literature management. The content-based and personalized literature recommendation helps researchers to isolate interesting papers from the "tsunami" of literature, in which, on average, more than one biomedical paper is added to MEDLINE every minute. Because researchers these days need to cover updates of much wider topics to generate hypotheses using massive datasets obtained from public databases or omics experiments, the importance of having an effective literature recommendation service is rising. The automatic recommendation is based on the content of personal literature libraries of electronic PDF papers. The client program automatically analyzes these files, which are sometimes deeply buried in storage disks of researchers' personal computers. Just saving PDF papers to the designated folders makes the client program automatically analyze and retrieve metadata, rename file names, synchronize the data to the server, and receive the recommendation lists of newly published papers, thus accomplishing effortless literature management. In addition, the tag suggestion and associative search functions are provided for easy classification of and access to past papers (researchers who read many papers sometimes only vaguely remember or completely forget what they read in the past). The TogoDoc system is available for both Windows and Mac OS X and is free. The TogoDoc Client software is available at http://tdc.cb.k.u-tokyo.ac.jp/, and the TogoDoc server is available at https://docman.dbcls.jp/pubmed_recom.

Evaluation of a server-client architecture for accelerator modeling and simulation

International Nuclear Information System (INIS)

Bowling, B.A.; Akers, W.; Shoaee, H.; Watson, W.; Zeijts, J. van; Witherspoon, S.

1997-01-01

Traditional approaches to computational modeling and simulation often utilize a batch method for code execution using file-formatted input/output. This method of code implementation was generally chosen for several factors, including CPU throughput and availability, complexity of the required modeling problem, and presentation of computation results. With the advent of faster computer hardware and the advances in networking and software techniques, other program architectures for accelerator modeling have recently been employed. Jefferson Laboratory has implemented a client/server solution for accelerator beam transport modeling utilizing a query-based I/O. The goal of this code is to provide modeling information for control system applications and to serve as a computation engine for general modeling tasks, such as machine studies. This paper performs a comparison between the batch execution and server/client architectures, focusing on design and implementation issues, performance, and general utility towards accelerator modeling demands

Robust client/server shared state interactions of collaborative process with system crash and network failures

NARCIS (Netherlands)

Wang, Lei; Wombacher, Andreas; Ferreira Pires, Luis; van Sinderen, Marten J.; Chi, Chihung

With the possibility of system crashes and network failures, the design of robust client/server interactions for collaborative process execution is a challenge. If a business process changes state, it sends messages to relevant processes to inform about this change. However, server crashes and

Energy-Reduction Offloading Technique for Streaming Media Servers

Directory of Open Access Journals (Sweden)

Yeongpil Cho

2016-01-01

Full Text Available Recent growth in popularity of mobile video services raises a demand for one of the most popular and convenient methods of delivering multimedia data, video streaming. However, heterogeneity of currently existing mobile devices involves an issue of separate video transcoding for each type of mobile devices such as smartphones, tablet PCs, and smart TVs. As a result additional burden comes to media servers, which pretranscode multimedia data for number of clients. Regarding even higher increase of video data in the Internet in the future, the problem of media servers overload is impending. To struggle against the problem an offloading method is introduced in this paper. By the use of SorTube offloading framework video transcoding process is shifted from the centralized media server to the local offloading server. Thus, clients can receive personally customized video stream; meanwhile the overload of centralized servers is reduced.

OVERVIEW OF POPULAR APPROACHES IN CREATING CLIENT-SERVER APPLICATIONS BASED ON SCIENTOMETRICS ONAFTS’ PLATFORM

Directory of Open Access Journals (Sweden)

D. Salskyi

2017-12-01

Full Text Available Most of the currently developed systems are based on the client-server architecture. This architecture is usedeverywhere, from mobile-native development to Web applications.However implementing an application based on this architectural solution requires quite a lot of effort from the softwaredeveloper, and therefore, in order to simplify and speed up the development, certain standard solutions and approachesappeared. This article will discuss the most popular technologies used in the development of Web applications in the context ofenterprise development.Also in this article will be mentioned the project, built on the architecture of "client-server" - ScienceToMetrics.The main theme of this project is the study of science-metric indicators for the structural divisions of the faculty of theOdessa National Academy of Food Technologies. In fact, it is a portal for viewing and editing information on employees, inthe future this portal may be extended to subprojects.In this project, the main idea of this architecture was embodied: decomposition of the application into atomic parts inorder to distribute it to several hardware units of capacity to improve performance. The client is an independent application,which at the same time receives information from an external API-interface through REST-requests. In turn, the backendprovides this API with certain security restrictions on the content provided. The backend for this architecture provides a layerfor the content of the data users, whether it's a database (NoSQL, SQL or an integration API with external aggregationsystems. To ensure the necessary level of security, JWT (Javascript Web Token authorization is used, which allows you not tocreate an explicit session between the client and the backend, but allows you to communicate through a token that stores allthe necessary meta-information for this user.

Client-server Approach in the Navigation System for the Blind

Directory of Open Access Journals (Sweden)

Lukasz Markiewicz

2013-09-01

Full Text Available The article presents the client-server approach in the navigation system for the blind - “Voice Maps”. The authors were among the main creators of the prototype and currently the commercialization phase is being finished. In the implemented prototype only exemplary, limited spatial data were used, therefore they could be stored and analyzed (for pathfinding process in the mobile device’s memory without any difficulties. The resulting increase of spatial data scale and complexity required a modification of the data storage and operation. Consequently, the decision was made to maintain a central spatial database, which is accessed remotely. After that modification, the mobile application fetches the required batch of spatial data (with the pathfinding and search results from the central server through the mobile internet connection, which has also become necessary for other purposes (e.g. voice recognition. The authors present the advantages and disadvantages of this new approach along with the results of the server operational tests.

FRIEND Engine Framework: a real time neurofeedback client-server system for neuroimaging studies

Science.gov (United States)

Basilio, Rodrigo; Garrido, Griselda J.; Sato, João R.; Hoefle, Sebastian; Melo, Bruno R. P.; Pamplona, Fabricio A.; Zahn, Roland; Moll, Jorge

2015-01-01

In this methods article, we present a new implementation of a recently reported FSL-integrated neurofeedback tool, the standalone version of “Functional Real-time Interactive Endogenous Neuromodulation and Decoding” (FRIEND). We will refer to this new implementation as the FRIEND Engine Framework. The framework comprises a client-server cross-platform solution for real time fMRI and fMRI/EEG neurofeedback studies, enabling flexible customization or integration of graphical interfaces, devices, and data processing. This implementation allows a fast setup of novel plug-ins and frontends, which can be shared with the user community at large. The FRIEND Engine Framework is freely distributed for non-commercial, research purposes. PMID:25688193

FRIEND Engine Framework: A real time neurofeedback client-server system for neuroimaging studies

Directory of Open Access Journals (Sweden)

Rodrigo eBasilio

2015-01-01

Full Text Available In this methods article, we present a new implementation of a recently reported FSL-integrated neurofeedback tool, the standalone version of Functional Real-time Interactive Endogenous Modulation and Decoding (FRIEND. We will refer to this new implementation as the FRIEND Engine Framework. The framework comprises a client-server cross-platform solution for real time fMRI and fMRI/EEG neurofeedback studies, enabling flexible customization or integration of graphical interfaces, devices and data processing. This implementation allows a fast setup of novel plug-ins and frontends, which can be shared with the user community at large. The FRIEND Engine Framework is freely distributed for non-commercial, research purposes.

Client Mobile Software Design Principles for Mobile Learning Systems

Directory of Open Access Journals (Sweden)

Qing Tan

2009-01-01

Full Text Available In a client-server mobile learning system, client mobile software must run on the mobile phone to acquire, package, and send student’s interaction data via the mobile communications network to the connected mobile application server. The server will receive and process the client data in order to offer appropriate content and learning activities. To develop the mobile learning systems there are a number of very important issues that must be addressed. Mobile phones have scarce computing resources. They consist of heterogeneous devices and use various mobile operating systems, they have limitations with their user/device interaction capabilities, high data communications cost, and must provide for device mobility and portability. In this paper we propose five principles for designing Client mobile learning software. A location-based adaptive mobile learning system is presented as a proof of concept to demonstrate the applicability of these design principles.

Rancang Bangun Keanggotaan Perpustakaan STT Telematika Telkom Menggunakan RFID Berbasis Java 2 Standard Edition Dengan Konsep Client Server

Directory of Open Access Journals (Sweden)

Yana Yuniarsyah

2013-05-01

Full Text Available RFID technology is a new technology that hasn’t been widely applied. The existence of this technology can reduce the disadvantages of barcode technology. One application of RFID technology is used for a library card. STT Telematika Library is a library that uses a membership card to borrow and return transactions only. The existence of RFID technology in the card member can create a multifunctional card, in addition to borrow and return books transactions, membership cards can be used for visitor attendance too. Distribution of visitor attendance and report library using client-server concept, thus make it easier for librarians in data management. The programming language used in the design of Library Information System is a Java 2 Standard Edition (J2SE using NetBeans 7.0 as IDE. Storage Library using the MySQL database. Software design method using waterfall or linear sequential models. Model design to make information sistem using Unified Modeling Language (UML like usecase diagram, activity diagram, and class diagram. Database design model using Entity Relationship Diagram (ERD for development information library system. Testing library information system have form with testing user requirements, test the program using blacbox testing, and testing the user. RFID used for library information systems have form such as RFID reader which used to read the information carried by the RFID tag and RFID tag used to transmit information to the RFID reader. The success of the client-server concept comes from the success of visitor attendance and show a report from the client, and the success of server to store visitor attendance data.

TRAP: A Three-Way Handshake Server for TCP Connection Establishment

Directory of Open Access Journals (Sweden)

Fu-Hau Hsu

2016-11-01

Full Text Available Distributed denial of service attacks have become more and more frequent nowadays. In 2013, a massive distributed denial of service (DDoS attack was launched against Spamhaus causing the service to shut down. In this paper, we present a three-way handshaking server for Transmission Control Protocol (TCP connection redirection utilizing TCP header options. When a legitimate client attempted to connect to a server undergoing an SYN-flood DDoS attack, it will try to initiate a three-way handshake. After it has successfully established a connection, the server will reply with a reset (RST packet, in which a new server address and a secret is embedded. The client can, thus, connect to the new server that only accepts SYN packets with the corrected secret using the supplied secret.

Distributed open environment for data retrieval based on pattern recognition techniques

International Nuclear Information System (INIS)

Pereira, A.; Vega, J.; Castro, R.; Portas, A.

2010-01-01

Pattern recognition methods for data retrieval have been applied to fusion databases for the localization and extraction of similar waveforms within temporal evolution signals. In order to standardize the use of these methods, a distributed open environment has been designed. It is based on a client/server architecture that supports distribution, interoperability and portability between heterogeneous platforms. The server part is a single desktop application based on J2EE (Java 2 Enterprise Edition), which provides a mature standard framework and a modular architecture. It can handle transactions and concurrency of components that are deployed on JETTY, an embedded web container within the Java server application for providing HTTP services. The data management is based on Apache DERBY, a relational database engine also embedded on the same Java based solution. This encapsulation allows hiding of unnecessary details about the installation, distribution, and configuration of all these components but with the flexibility to create and allocate many databases on different servers. The DERBY network module increases the scope of the installed database engine by providing traditional Java database network connections (JDBC-TCP/IP). This avoids scattering several database engines (a unique embedded engine defines the rules for accessing the distributed data). Java thin clients (Java 5 or above is the unique requirement) can be executed in the same computer than the server program (for example a desktop computer) but also server and client software can be distributed in a remote participation environment (wide area networks). The thin client provides graphic user interface to look for patterns (entire waveforms or specific structural forms) and display the most similar ones. This is obtained with HTTP requests and by generating dynamic content (servlets) in response to these client requests.

Distributed Open Environment for Data Retrieval based on Pattern Recognition Techniques

Energy Technology Data Exchange (ETDEWEB)

Pereira, A.; Vega, J.; Castro, R.; Portas, A. [Association EuratomCIEMAT para Fusion, Madrid (Spain)

2009-07-01

Full text of publication follows: Pattern recognition methods for data retrieval have been applied to fusion databases for the localization and extraction of similar waveforms within temporal evolution signals. In order to standardize the use of these methods, a distributed open environment has been designed. It is based on a client/server architecture that supports distribution, inter-operability and portability between heterogeneous platforms. The server part is a single desktop application based on J2EE, which provides a mature standard framework and a modular architecture. It can handle transactions and competition of components that are deployed on JETTY, an embedded web container within the Java server application for providing HTTP services. The data management is based on Apache DERBY, a relational database engine also embedded on the same Java based solution. This encapsulation allows concealment of unnecessary details about the installation, distribution, and configuration of all these components but with the flexibility to create and allocate many databases on different servers. The DERBY network module increases the scope of the installed database engine by providing traditional Java database network connections (JDBC-TCP/IP). This avoids scattering several database engines (a unique embedded engine defines the rules for accessing the distributed data). Java thin clients (Java 5 or above is the unique requirement) can be executed in the same computer than the server program (for example a desktop computer) but also server and client software can be distributed in a remote participation environment (wide area networks). The thin client provides graphic user interface to look for patterns (entire waveforms or specific structural forms) and display the most similar ones. This is obtained with HTTP requests and by generating dynamic content (servlets) in response to these client requests. (authors)

Distributed open environment for data retrieval based on pattern recognition techniques

Energy Technology Data Exchange (ETDEWEB)

Pereira, A., E-mail: augusto.pereira@ciemat.e [Asociacion EURATOM/CIEMAT para Fusion, CIEMAT, Edificio 66, Avda. Complutense, 22, 28040 Madrid (Spain); Vega, J.; Castro, R.; Portas, A. [Asociacion EURATOM/CIEMAT para Fusion, CIEMAT, Edificio 66, Avda. Complutense, 22, 28040 Madrid (Spain)

2010-07-15

Pattern recognition methods for data retrieval have been applied to fusion databases for the localization and extraction of similar waveforms within temporal evolution signals. In order to standardize the use of these methods, a distributed open environment has been designed. It is based on a client/server architecture that supports distribution, interoperability and portability between heterogeneous platforms. The server part is a single desktop application based on J2EE (Java 2 Enterprise Edition), which provides a mature standard framework and a modular architecture. It can handle transactions and concurrency of components that are deployed on JETTY, an embedded web container within the Java server application for providing HTTP services. The data management is based on Apache DERBY, a relational database engine also embedded on the same Java based solution. This encapsulation allows hiding of unnecessary details about the installation, distribution, and configuration of all these components but with the flexibility to create and allocate many databases on different servers. The DERBY network module increases the scope of the installed database engine by providing traditional Java database network connections (JDBC-TCP/IP). This avoids scattering several database engines (a unique embedded engine defines the rules for accessing the distributed data). Java thin clients (Java 5 or above is the unique requirement) can be executed in the same computer than the server program (for example a desktop computer) but also server and client software can be distributed in a remote participation environment (wide area networks). The thin client provides graphic user interface to look for patterns (entire waveforms or specific structural forms) and display the most similar ones. This is obtained with HTTP requests and by generating dynamic content (servlets) in response to these client requests.

SSDL personel dosimetry system: migration from a client - server system into a web-based system

International Nuclear Information System (INIS)

Maizura Ibrahim; Rosnah Shariff; Ahmad Bazlie Abdul Kadir; John Konsoh Sangau; Mohd Amin Sharifuldin Salleh; Taiman Kadni; Noriah Mod Ali

2007-01-01

Personnel Dosimetry System has been used by the Secondary Standard Dosimetry Laboratory (SSDL), Nuclear Malaysia since ten years ago. The system is a computerized database system with a client-server concept. This system has been used by Film Badge Laboratory, SSDL to record details of clients, calculation of Film Badge dosage, management of radiation workers data's, generating of dosage report, retrieval of statistical reports regarding film badge usage for the purpose of reporting to monitoring bodies such as Atomic Energy Licensing Board (AELB), Ministry of Health and others. But, due to technical problems that frequently occurs, the system is going to be replaced by a newly developed web- based system called e-SSDL. This paper describe the problems that regularly occurs in the previous system, explains how the process of replacing the client-server system with a web-based system is done and the differences between the previous and current system. This paper will also present details architecture of the new system and the new process introduced in processing film badges. (Author)

The X-Files Investigating Alien Performance in a Thin-client World

CERN Document Server

Gunther, N J

2000-01-01

Many scientific applications use the X11 window environment; an open source windows GUI standard employing a client/server architecture. X11 promotes: distributed computing, thin-client functionality, cheap desktop displays, compatibility with heterogeneous servers, remote services and administration, and greater maturity than newer web technologies. This paper details the author's investigations into close encounters with alien performance in X11-based seismic applications running on a 200-node cluster, backed by 2 TB of mass storage. End-users cited two significant UFOs (Unidentified Faulty Operations) i) long application launch times and ii) poor interactive response times. The paper is divided into three major sections describing Close Encounters of the 1st Kind: citings of UFO experiences, the 2nd Kind: recording evidence of a UFO, and the 3rd Kind: contact and analysis. UFOs do exist and this investigation presents a real case study for evaluating workload analysis and other diagnostic tools.

Indoor Location Fingerprinting with Heterogeneous Clients

DEFF Research Database (Denmark)

Kjærgaard, Mikkel Baun

2011-01-01

Heterogeneous wireless clients measure signal strength differently. This is a fundamental problem for indoor location fingerprinting, and it has a high impact on the positioning accuracy. Mapping-based solutions have been presented that require manual and error-prone calibration for each new clie...

Prototype for a generic thin-client remote analysis environment for CMS

International Nuclear Information System (INIS)

Steenberg, C.D.; Bunn, J.J.; Hickey, T.M.; Holtman, K.; Legrand, I.; Litvin, V.; Newman, H.B.; Samar, A.; Singh, S.; Wilkinson, R.

2001-01-01

The multi-tiered architecture of the highly-distributed CMS computing systems necessitates a flexible data distribution and analysis environment. The authors describe a prototype analysis environment which functions efficiently over wide area networks using a server installed at the Caltech/UCSD Tier 2 prototype to analyze CMS data stored at various locations using a thin client. The analysis environment is based on existing HEP (Anaphe) and CMS (CARF, ORCA, IGUANA) software technology on the server accessed from a variety of clients. A Java Analysis Studio (JAS, from SLAC) plug-in is being developed as a reference client. The server is operated as a 'black box' on the proto-Tier2 system. ORCA objectivity databases (e.g. an existing large CMS Muon sample) are hosted on the master and slave nodes, and remote clients can request processing of queries across the server nodes, and get the histogram results returned and rendered in the client. The server is implemented using pure C++, and use XML-RPC as a language-neutral transport. This has several benefits, including much better scalability, better integration with CARF-ORCA, and importantly, makes the work directly useful to other non-Java general-purpose analysis and presentation tools such as Hippodraw, Lizard, or ROOT

Benchmark of Client and Server-Side Catchment Delineation Approaches on Web-Based Systems

Science.gov (United States)

Demir, I.; Sermet, M. Y.; Sit, M. A.

2016-12-01

Recent advances in internet and cyberinfrastructure technologies have provided the capability to acquire large scale spatial data from various gauges and sensor networks. The collection of environmental data increased demand for applications which are capable of managing and processing large-scale and high-resolution data sets. With the amount and resolution of data sets provided, one of the challenging tasks for organizing and customizing hydrological data sets is delineation of watersheds on demand. Watershed delineation is a process for creating a boundary that represents the contributing area for a specific control point or water outlet, with intent of characterization and analysis of portions of a study area. Although many GIS tools and software for watershed analysis are available on desktop systems, there is a need for web-based and client-side techniques for creating a dynamic and interactive environment for exploring hydrological data. In this project, we demonstrated several watershed delineation techniques on the web with various techniques implemented on the client-side using JavaScript and WebGL, and on the server-side using Python and C++. We also developed a client-side GPGPU (General Purpose Graphical Processing Unit) algorithm to analyze high-resolution terrain data for watershed delineation which allows parallelization using GPU. The web-based real-time analysis of watershed segmentation can be helpful for decision-makers and interested stakeholders while eliminating the need of installing complex software packages and dealing with large-scale data sets. Utilization of the client-side hardware resources also eliminates the need of servers due its crowdsourcing nature. Our goal for future work is to improve other hydrologic analysis methods such as rain flow tracking by adapting presented approaches.

Remote information service access system based on a client-server-service model

Science.gov (United States)

Konrad, A.M.

1996-08-06

A local host computing system, a remote host computing system as connected by a network, and service functionalities: a human interface service functionality, a starter service functionality, and a desired utility service functionality, and a Client-Server-Service (CSS) model is imposed on each service functionality. In one embodiment, this results in nine logical components and three physical components (a local host, a remote host, and an intervening network), where two of the logical components are integrated into one Remote Object Client component, and that Remote Object Client component and the other seven logical components are deployed among the local host and remote host in a manner which eases compatibility and upgrade problems, and provides an illusion to a user that a desired utility service supported on a remote host resides locally on the user`s local host, thereby providing ease of use and minimal software maintenance for users of that remote service. 16 figs.

PONDEROSA-C/S: client-server based software package for automated protein 3D structure determination.

Science.gov (United States)

Lee, Woonghee; Stark, Jaime L; Markley, John L

2014-11-01

Peak-picking Of Noe Data Enabled by Restriction Of Shift Assignments-Client Server (PONDEROSA-C/S) builds on the original PONDEROSA software (Lee et al. in Bioinformatics 27:1727-1728. doi: 10.1093/bioinformatics/btr200, 2011) and includes improved features for structure calculation and refinement. PONDEROSA-C/S consists of three programs: Ponderosa Server, Ponderosa Client, and Ponderosa Analyzer. PONDEROSA-C/S takes as input the protein sequence, a list of assigned chemical shifts, and nuclear Overhauser data sets ((13)C- and/or (15)N-NOESY). The output is a set of assigned NOEs and 3D structural models for the protein. Ponderosa Analyzer supports the visualization, validation, and refinement of the results from Ponderosa Server. These tools enable semi-automated NMR-based structure determination of proteins in a rapid and robust fashion. We present examples showing the use of PONDEROSA-C/S in solving structures of four proteins: two that enable comparison with the original PONDEROSA package, and two from the Critical Assessment of automated Structure Determination by NMR (Rosato et al. in Nat Methods 6:625-626. doi: 10.1038/nmeth0909-625 , 2009) competition. The software package can be downloaded freely in binary format from http://pine.nmrfam.wisc.edu/download_packages.html. Registered users of the National Magnetic Resonance Facility at Madison can submit jobs to the PONDEROSA-C/S server at http://ponderosa.nmrfam.wisc.edu, where instructions, tutorials, and instructions can be found. Structures are normally returned within 1-2 days.

Client-server computer architecture saves costs and eliminates bottlenecks

International Nuclear Information System (INIS)

Darukhanavala, P.P.; Davidson, M.C.; Tyler, T.N.; Blaskovich, F.T.; Smith, C.

1992-01-01

This paper reports that workstation, client-server architecture saved costs and eliminated bottlenecks that BP Exploration (Alaska) Inc. experienced with mainframe computer systems. In 1991, BP embarked on an ambitious project to change technical computing for its Prudhoe Bay, Endicott, and Kuparuk operations on Alaska's North Slope. This project promised substantial rewards, but also involved considerable risk. The project plan called for reservoir simulations (which historically had run on a Cray Research Inc. X-MP supercomputer in the company's Houston data center) to be run on small computer workstations. Additionally, large Prudhoe Bay, Endicott, and Kuparuk production and reservoir engineering data bases and related applications also would be moved to workstations, replacing a Digital Equipment Corp. VAX cluster in Anchorage

Personalized Pseudonyms for Servers in the Cloud

Directory of Open Access Journals (Sweden)

Xiao Qiuyu

2017-10-01

Full Text Available A considerable and growing fraction of servers, especially of web servers, is hosted in compute clouds. In this paper we opportunistically leverage this trend to improve privacy of clients from network attackers residing between the clients and the cloud: We design a system that can be deployed by the cloud operator to prevent a network adversary from determining which of the cloud’s tenant servers a client is accessing. The core innovation in our design is a PoPSiCl (pronounced “popsicle”, a persistent pseudonym for a tenant server that can be used by a single client to access the server, whose real identity is protected by the cloud from both passive and active network attackers. When instantiated for TLS-based access to web servers, our design works with all major browsers and requires no additional client-side software and minimal changes to the client user experience. Moreover, changes to tenant servers can be hidden in supporting software (operating systems and web-programming frameworks without imposing on web-content development. Perhaps most notably, our system boosts privacy with minimal impact to web-browsing performance, after some initial setup during a user’s first access to each web server.

Development of a Personal Digital Assistant (PDA) based client/server NICU patient data and charting system.

Science.gov (United States)

Carroll, A E; Saluja, S; Tarczy-Hornoch, P

2001-01-01

Personal Digital Assistants (PDAs) offer clinicians the ability to enter and manage critical information at the point of care. Although PDAs have always been designed to be intuitive and easy to use, recent advances in technology have made them even more accessible. The ability to link data on a PDA (client) to a central database (server) allows for near-unlimited potential in developing point of care applications and systems for patient data management. Although many stand-alone systems exist for PDAs, none are designed to work in an integrated client/server environment. This paper describes the design, software and hardware selection, and preliminary testing of a PDA based patient data and charting system for use in the University of Washington Neonatal Intensive Care Unit (NICU). This system will be the subject of a subsequent study to determine its impact on patient outcomes and clinician efficiency.

The ARAC client system: network-based access to ARAC

International Nuclear Information System (INIS)

Leach, M J; Sumikawa, D; Webster, C

1999-01-01

The ARAC Client System allows users (such as emergency managers and first responders) with commonly available desktop and laptop computers to utilize the central ARAC system over the Internet or any other communications link using Internet protocols. Providing cost-effective fast access to the central ARAC system greatly expands the availability of the ARAC capability. The ARAC Client system consists of (1) local client applications running on the remote user's computer, and (2) ''site servers'' that provide secure access to selected central ARAC system capabilities and run on a scalable number of dedicated workstations residing at the central facility. The remote client applications allow users to describe a real or potential them-bio event, electronically sends this information to the central ARAC system which performs model calculations, and quickly receive and visualize the resulting graphical products. The site servers will support simultaneous access to ARAC capabilities by multiple users. The ARAC Client system is based on object-oriented client/server and distributed computing technologies using CORBA and Java, and consists of a large number of interacting components

Building mail server on distributed computing system

International Nuclear Information System (INIS)

Akihiro Shibata; Osamu Hamada; Tomoko Oshikubo; Takashi Sasaki

2001-01-01

The electronic mail has become the indispensable function in daily job, and the server stability and performance are required. Using DCE and DFS we have built the distributed electronic mail sever, that is, servers such as SMTP, IMAP are distributed symmetrically, and provides the seamless access

Triple-server blind quantum computation using entanglement swapping

Science.gov (United States)

Li, Qin; Chan, Wai Hong; Wu, Chunhui; Wen, Zhonghua

2014-04-01

Blind quantum computation allows a client who does not have enough quantum resources or technologies to achieve quantum computation on a remote quantum server such that the client's input, output, and algorithm remain unknown to the server. Up to now, single- and double-server blind quantum computation have been considered. In this work, we propose a triple-server blind computation protocol where the client can delegate quantum computation to three quantum servers by the use of entanglement swapping. Furthermore, the three quantum servers can communicate with each other and the client is almost classical since one does not require any quantum computational power, quantum memory, and the ability to prepare any quantum states and only needs to be capable of getting access to quantum channels.

A Graphical Client-Server Approach to Financial Management

CERN Document Server

Möller, M

1994-01-01

At the European Laboratory for Particle Physics (CERN), we have an annual budget of around 600 million US dollars. In order to manage this budget successfully, fast, accurate and easy information access is required throughout the management hierarchy. To meet these goals we have focused on the powerful combination of Relational Database Technology, Fourth Generation Tools and Client-Server architecture. Using these technologies we have developed a powerful and easy-to-use management information tool (known as the BHT) which allows the follow up and tracking of expenditure at all levels throughout the organization. Executives may instantaneously produce up-to-date graphics showing the expenditure profile of the organization. These graphics may then be used as a basis for ‘zooming in’ to view more and more details until the individual financial transactions are reached (all of which are on-line and available on the user’s desktop). The graphical user interface runs on both Macintosh and PC. Using ORACLE�...

Distributed monitoring system based on Icinga

International Nuclear Information System (INIS)

Haen, C.; Bonaccorsi, E.; Neufeld, N.

2012-01-01

The LHCb online system relies on a large and heterogeneous IT infrastructure: it comprises more than 2000 servers and embedded systems and more than 200 network devices. Many of these equipment are critical in order to run the experiment, and it is important to have a monitoring solution efficient enough so that the experts can diagnose and act quickly. While our previous system was based on a central Nagios server, our current system uses a distributed Icinga infrastructure. We have a single instance of Icinga that schedules the checks and deals with the results but we have other servers (called 'workers') to perform the checks. The load induced on the worker is negligible, whereas the central server is fully busy. A client/server model based on Gearman manages queues the clients use to get their tasks and give their results. The other interesting feature of Icinga is the database back-end. Icinga will log the result of every action and check-result in a database. The new installation is now running 36000 service checks on 2100 hosts with 50 Gearman workers. Performances have dramatically improved

Parallel Computing Using Web Servers and "Servlets".

Science.gov (United States)

Lo, Alfred; Bloor, Chris; Choi, Y. K.

2000-01-01

Describes parallel computing and presents inexpensive ways to implement a virtual parallel computer with multiple Web servers. Highlights include performance measurement of parallel systems; models for using Java and intranet technology including single server, multiple clients and multiple servers, single client; and a comparison of CGI (common…

Rancang Bangun Aplikasi Pembayaran Sekolah Menggunakan Java Dan MySQL Berbasis Client Server Di SMA Yos Sudarso Cilacap

Directory of Open Access Journals (Sweden)

Elisa Usada

2010-11-01

Full Text Available SMA Yos Sudarso merupakan salah satu sekolah yang sudah memanfaatkan komputer  untuk menyelesaikan berbagai macam tugas, tetapi pemanfaatannya masih belum maksimal karena ada bagian administrasi yang masih menggunakan metode manual, yaitu pada administrasi pembayaran. Penelitian ini  berusaha membuat sebuah aplikasi client server berteknologi JAVA dan MySQL untuk mengelola data pembayaran sekolah meliputi pembayaran SPP, pembayaran uang gedung serta pembayaran ujian. Metode waterfall digunakan sebagai acuan perancangan dan pengembangan aplikasi. Alat abstraksi sistem yang digunakan adalah use case diagram dan class diagram. Perancangan basis data dengan menggunakan ERD. Pengujian dilakukan dengan metode black box yaitu hanya menguji jalannya fungsi-fungsi yang telah direncanakan tanpa mempedulikan aspek proses internal dalam kode dan algoritma. Pengujian memberikan hasil bahwa aplikasi dapat dijalankan secara client server dan fungsi dapat berjalan semestinya. Proses back up data otomatis menjadi kekurangan dari aplikasi dalam penelitian ini.

Personalized Pseudonyms for Servers in the Cloud

OpenAIRE

Xiao Qiuyu; Reiter Michael K.; Zhang Yinqian

2017-01-01

A considerable and growing fraction of servers, especially of web servers, is hosted in compute clouds. In this paper we opportunistically leverage this trend to improve privacy of clients from network attackers residing between the clients and the cloud: We design a system that can be deployed by the cloud operator to prevent a network adversary from determining which of the cloud’s tenant servers a client is accessing. The core innovation in our design is a PoPSiCl (pronounced “popsicle”), ...

Asynchronous data change notification between database server and accelerator control systems

International Nuclear Information System (INIS)

Wenge Fu; Seth Nemesure; Morris, J.

2012-01-01

Database data change notification (DCN) is a commonly used feature, it allows to be informed when the data has been changed on the server side by another client. Not all database management systems (DBMS) provide an explicit DCN mechanism. Even for those DBMS's which support DCN (such as Oracle and MS SQL server), some server side and/or client side programming may be required to make the DCN system work. This makes the setup of DCN between database server and interested clients tedious and time consuming. In accelerator control systems, there are many well established software client/server architectures (such as CDEV, EPICS, and ADO) that can be used to implement data reflection servers that transfer data asynchronously to any client using the standard SET/GET API. This paper describes a method for using such a data reflection server to set up asynchronous DCN (ADCN) between a DBMS and clients. This method works well for all DBMS systems which provide database trigger functionality. (authors)

Collectives for Multiple Resource Job Scheduling Across Heterogeneous Servers

Science.gov (United States)

Tumer, K.; Lawson, J.

2003-01-01

Efficient management of large-scale, distributed data storage and processing systems is a major challenge for many computational applications. Many of these systems are characterized by multi-resource tasks processed across a heterogeneous network. Conventional approaches, such as load balancing, work well for centralized, single resource problems, but breakdown in the more general case. In addition, most approaches are often based on heuristics which do not directly attempt to optimize the world utility. In this paper, we propose an agent based control system using the theory of collectives. We configure the servers of our network with agents who make local job scheduling decisions. These decisions are based on local goals which are constructed to be aligned with the objective of optimizing the overall efficiency of the system. We demonstrate that multi-agent systems in which all the agents attempt to optimize the same global utility function (team game) only marginally outperform conventional load balancing. On the other hand, agents configured using collectives outperform both team games and load balancing (by up to four times for the latter), despite their distributed nature and their limited access to information.

Client-server password recovery

NARCIS (Netherlands)

Chmielewski, Ł.; Hoepman, J.H.; Rossum, P. van

2009-01-01

Human memory is not perfect - people constantly memorize new facts and forget old ones. One example is forgetting a password, a common problem raised at IT help desks. We present several protocols that allow a user to automatically recover a password from a server using partial knowledge of the

Server consolidation for heterogeneous computer clusters using Colored Petri Nets and CPN Tools

Directory of Open Access Journals (Sweden)

Issam Al-Azzoni

2015-10-01

Full Text Available In this paper, we present a new approach to server consolidation in heterogeneous computer clusters using Colored Petri Nets (CPNs. Server consolidation aims to reduce energy costs and improve resource utilization by reducing the number of servers necessary to run the existing virtual machines in the cluster. It exploits the emerging technology of live migration which allows migrating virtual machines between servers without stopping their provided services. Server consolidation approaches attempt to find migration plans that aim to minimize the necessary size of the cluster. Our approach finds plans which not only minimize the overall number of used servers, but also minimize the total data migration overhead. The latter objective is not taken into consideration by other approaches and heuristics. We explore the use of CPN Tools in analyzing the state spaces of the CPNs. Since the state space of the CPN model can grow exponentially with the size of the cluster, we examine different techniques to generate and analyze the state space in order to find good plans to server consolidation within acceptable time and computing power.

Client-Server Password Recovery

NARCIS (Netherlands)

Chmielewski, L.; Hoepman, J.H.; Rossum, P. van

2009-01-01

Human memory is not perfect – people constantly memorize new facts and forget old ones. One example is forgetting a password, a common problem raised at IT help desks. We present several protocols that allow a user to automatically recover a password from a server using partial knowledge of the

A smartphone client-server teleradiology system for primary diagnosis of acute stroke.

Science.gov (United States)

Mitchell, J Ross; Sharma, Pranshu; Modi, Jayesh; Simpson, Mark; Thomas, Monroe; Hill, Michael D; Goyal, Mayank

2011-05-06

Recent advances in the treatment of acute ischemic stroke have made rapid acquisition, visualization, and interpretation of images a key factor for positive patient outcomes. We have developed a new teleradiology system based on a client-server architecture that enables rapid access to interactive advanced 2-D and 3-D visualization on a current generation smartphone device (Apple iPhone or iPod Touch, or an Android phone) without requiring patient image data to be stored on the device. Instead, a server loads and renders the patient images, then transmits a rendered frame to the remote device. Our objective was to determine if a new smartphone client-server teleradiology system is capable of providing accuracies and interpretation times sufficient for diagnosis of acute stroke. This was a retrospective study. We obtained 120 recent consecutive noncontrast computed tomography (NCCT) brain scans and 70 computed tomography angiogram (CTA) head scans from the Calgary Stroke Program database. Scans were read by two neuroradiologists, one on a medical diagnostic workstation and an iPod or iPhone (hereafter referred to as an iOS device) and the other only on an iOS device. NCCT brain scans were evaluated for early signs of infarction, which includes early parenchymal ischemic changes and dense vessel sign, and to exclude acute intraparenchymal hemorrhage and stroke mimics. CTA brain scans were evaluated for any intracranial vessel occlusion. The interpretations made on an iOS device were compared with those made at a workstation. The total interpretation times were recorded for both platforms. Interrater agreement was assessed. True positives, true negatives, false positives, and false negatives were obtained, and sensitivity, specificity, and accuracy of detecting the abnormalities on the iOS device were computed. The sensitivity, specificity, and accuracy of detecting intraparenchymal hemorrhage were 100% using the iOS device with a perfect interrater agreement (kappa=1

Asynchronous data change notification between database server and accelerator controls system

International Nuclear Information System (INIS)

Fu, W.; Morris, J.; Nemesure, S.

2011-01-01

Database data change notification (DCN) is a commonly used feature. Not all database management systems (DBMS) provide an explicit DCN mechanism. Even for those DBMS's which support DCN (such as Oracle and MS SQL server), some server side and/or client side programming may be required to make the DCN system work. This makes the setup of DCN between database server and interested clients tedious and time consuming. In accelerator control systems, there are many well established software client/server architectures (such as CDEV, EPICS, and ADO) that can be used to implement data reflection servers that transfer data asynchronously to any client using the standard SET/GET API. This paper describes a method for using such a data reflection server to set up asynchronous DCN (ADCN) between a DBMS and clients. This method works well for all DBMS systems which provide database trigger functionality. Asynchronous data change notification (ADCN) between database server and clients can be realized by combining the use of a database trigger mechanism, which is supported by major DBMS systems, with server processes that use client/server software architectures that are familiar in the accelerator controls community (such as EPICS, CDEV or ADO). This approach makes the ADCN system easy to set up and integrate into an accelerator controls system. Several ADCN systems have been set up and used in the RHIC-AGS controls system.

EarthServer - 3D Visualization on the Web

Science.gov (United States)

Wagner, Sebastian; Herzig, Pasquale; Bockholt, Ulrich; Jung, Yvonne; Behr, Johannes

2013-04-01

EarthServer (www.earthserver.eu), funded by the European Commission under its Seventh Framework Program, is a project to enable the management, access and exploration of massive, multi-dimensional datasets using Open GeoSpatial Consortium (OGC) query and processing language standards like WCS 2.0 and WCPS. To this end, a server/client architecture designed to handle Petabyte/Exabyte volumes of multi-dimensional data is being developed and deployed. As an important part of the EarthServer project, six Lighthouse Applications, major scientific data exploitation initiatives, are being established to make cross-domain, Earth Sciences related data repositories available in an open and unified manner, as service endpoints based on solutions and infrastructure developed within the project. Clients technology developed and deployed in EarthServer ranges from mobile and web clients to immersive virtual reality systems, all designed to interact with a physically and logically distributed server infrastructure using exclusively OGC standards. In this contribution, we would like to present our work on a web-based 3D visualization and interaction client for Earth Sciences data using only technology found in standard web browsers without requiring the user to install plugins or addons. Additionally, we are able to run the earth data visualization client on a wide range of different platforms with very different soft- and hardware requirements such as smart phones (e.g. iOS, Android), different desktop systems etc. High-quality, hardware-accelerated visualization of 3D and 4D content in standard web browsers can be realized now and we believe it will become more and more common to use this fast, lightweight and ubiquitous platform to provide insights into big datasets without requiring the user to set up a specialized client first. With that in mind, we will also point out some of the limitations we encountered using current web technologies. Underlying the EarthServer web client

MPEG-4 interactive image transmission on mobile thin clients

Science.gov (United States)

Joveski, B.; Mitrea, M.; Pr"teux, F.

2010-05-01

The main issue in this paper is to deploy a compressing algorithm for heterogeneous content (text, graphics, image and video) with low-complex decoding. Such an algorithm will be involved in the remote display core problem for mobile thin clients: it allows the graphical content, computed on a remote server, to be displayer on the user's thin terminal, even when the network constraints (bandwidth, errors) are very strict. The paper is structured into three parts. First, a client-server architecture is presented. On the server side, the graphical content is parsed, converted and binary encoded into the MPEG 4 (BiFS, LASeR) format. This content is further streamed to the terminal, where it is played into a simple MPEG player. Secondly, this architecture is considered as a test bed for MPEG 4 performance assessment for various types of content (image, graphics, text). The quantitative results were focussed on bandwidth requirements and quality of experience. Finally, the conclusions are structured as a reference benchmarking of the MPEG (BiFS, LASeR) and outside (VNC) mobile remote display potential solutions.

Single-server queues with spatially distributed arrivals

NARCIS (Netherlands)

Kroese, Dirk; Schmidt, Volker

1994-01-01

Consider a queueing system where customers arrive at a circle according to a homogeneous Poisson process. After choosing their positions on the circle, according to a uniform distribution, they wait for a single server who travels on the circle. The server's movement is modelled by a Brownian motion

A GCM Solution for Leveraging Server-side JMS Functionality to Android-based Trading Application

Directory of Open Access Journals (Sweden)

Claudiu VINTE

2013-01-01

Full Text Available The paper presents our solution for a message oriented communication mechanism, employing Google Cloud Messaging (GCM on the client-side, and Java Message Service (JMS on the server-side, in order to leverage JMS functionality to Android-based trading application. Our ongoing research has been focused upon conceiving a way to expose the trading services offered by our academic trading system ASETS to a mobile trading application based on Android platform. ASETS trading platform is a distributed SOA implementation, with an original API based on JMS. In order to design and implement an Android based client, able to inter-communicate with the server-side components of ASETS, in a manner consistent with publisher/subscriber JMS communication model, there was particularly necessary to have object embedded messages, produced by various ASETS services, pushed to the client application. While point-to-point communication model could be resolved on the client-side by employing synchronous HTTP socket connections over TCP/IP, the asynchronously generated messages from the server-side had to reach the client application in a push manner.

Log-Less Metadata Management on Metadata Server for Parallel File Systems

Directory of Open Access Journals (Sweden)

Jianwei Liao

2014-01-01

Full Text Available This paper presents a novel metadata management mechanism on the metadata server (MDS for parallel and distributed file systems. In this technique, the client file system backs up the sent metadata requests, which have been handled by the metadata server, so that the MDS does not need to log metadata changes to nonvolatile storage for achieving highly available metadata service, as well as better performance improvement in metadata processing. As the client file system backs up certain sent metadata requests in its memory, the overhead for handling these backup requests is much smaller than that brought by the metadata server, while it adopts logging or journaling to yield highly available metadata service. The experimental results show that this newly proposed mechanism can significantly improve the speed of metadata processing and render a better I/O data throughput, in contrast to conventional metadata management schemes, that is, logging or journaling on MDS. Besides, a complete metadata recovery can be achieved by replaying the backup logs cached by all involved clients, when the metadata server has crashed or gone into nonoperational state exceptionally.

Server-side Statistics Scripting in PHP

Directory of Open Access Journals (Sweden)

Jan de Leeuw

1997-06-01

Full Text Available On the UCLA Statistics WWW server there are a large number of demos and calculators that can be used in statistics teaching and research. Some of these demos require substantial amounts of computation, others mainly use graphics. These calculators and demos are implemented in various different ways, reflecting developments in WWW based computing. As usual, one of the main choices is between doing the work on the client-side (i.e. in the browser or on the server-side (i.e. on our WWW server. Obviously, client-side computation puts fewer demands on the server. On the other hand, it requires that the client downloads Java applets, or installs plugins and/or helpers. If JavaScript is used, client-side computations will generally be slow. We also have to assume that the client is installed properly, and has the required capabilities. Requiring too much on the client-side has caused browsing machines such as Netscape Communicator to grow beyond all reasonable bounds, both in size and RAM requirements. Moreover requiring Java and JavaScript rules out such excellent browsers as Lynx or Emacs W3. For server-side computing, we can configure the server and its resources ourselves, and we need not worry about browser capabilities and configuration. Nothing needs to be downloaded, except the usual HTML pages and graphics. In the same way as on the client side, there is a scripting solution, where code is interpreted, or a ob ject-code solution using compiled code. For the server-side scripting, we use embedded languages, such as PHP/FI. The scripts in the HTML pages are interpreted by a CGI program, and the output of the CGI program is send to the clients. Of course the CGI program is compiled, but the statistics procedures will usually be interpreted, because PHP/FI does not have the appropriate functions in its scripting language. This will tend to be slow, because embedded languages do not deal efficiently with loops and similar constructs. Thus a first

Towards Direct Manipulation and Remixing of Massive Data: The EarthServer Approach

Science.gov (United States)

Baumann, P.

2012-04-01

all OGC coverage types. The platform used by EarthServer is the rasdaman raster database system. To exploit heterogeneous multi-parallel platforms, automatic request distribution and orchestration is being established. Client toolkits are under development which will allow to quickly compose bespoke interactive clients, ranging from mobile devices over Web clients to high-end immersive virtual reality. The EarthServer platform has been deployed in six large-scale data centres with the aim of setting up Lighthouse Applications addressing all Earth Sciences, including satellite and airborne earth observation as well as use cases from atmosphere, ocean, snow, and ice monitoring, and geology on Earth and Mars. These services, each of which will ultimately host at least 100 TB, will form a peer cloud with distributed query processing for arbitrarily mixing database and in-situ access. With its ability to directly manipulate, analyze and remix massive data, the goal of EarthServer is to lift the data providers' semantic level from data stewardship to service stewardship.

Single-server blind quantum computation with quantum circuit model

Science.gov (United States)

Zhang, Xiaoqian; Weng, Jian; Li, Xiaochun; Luo, Weiqi; Tan, Xiaoqing; Song, Tingting

2018-06-01

Blind quantum computation (BQC) enables the client, who has few quantum technologies, to delegate her quantum computation to a server, who has strong quantum computabilities and learns nothing about the client's quantum inputs, outputs and algorithms. In this article, we propose a single-server BQC protocol with quantum circuit model by replacing any quantum gate with the combination of rotation operators. The trap quantum circuits are introduced, together with the combination of rotation operators, such that the server is unknown about quantum algorithms. The client only needs to perform operations X and Z, while the server honestly performs rotation operators.

An M/M/2 Queueing System with Heterogeneous Servers Including One with Working Vacation

Directory of Open Access Journals (Sweden)

A. Krishnamoorthy

2012-01-01

Full Text Available This paper analyzes an M/M/2 queueing system with two heterogeneous servers, one of which is always available but the other goes on vacation in the absence of customers waiting for service. The vacationing server, however, returns to serve at a low rate as an arrival finds the other server busy. The system is analyzed in the steady state using matrix geometric method. Busy period of the system is analyzed and mean waiting time in the stationary regime computed. Conditional stochastic decomposition of stationary queue length is obtained. An illustrative example is also provided.

Client-Server and Peer-to-Peer Ad-hoc Network for a Flexible Learning Environment

Directory of Open Access Journals (Sweden)

Ferial Khaddage

2011-01-01

Full Text Available Peer-to-Peer (P2P networking in a mobile learning environment has become a popular topic of research. One of the new emerging research ideas is on the ability to combine P2P network with server-based network to form a strong efficient portable and compatible network infrastructure. This paper describes a unique mobile network architecture, which reflects the on-campus students’ need for a mobile learning environment. This can be achieved by combining two different networks, client-server and peer-to-peer ad-hoc to form a sold and secure network. This is accomplished by employing one peer within the ad-hoc network to act as an agent-peer to facilitate communication and information sharing between the two networks. It can be implemented without any major changes to the current network technologies, and can combine any wireless protocols such as GPRS, Wi-Fi, Bluetooth, and 3G.

Tree-based server-middleman-client architecture: improving scalability and reliability for voting-based network games in ad hoc wireless networks

Science.gov (United States)

Guo, Y.; Fujinoki, H.

2006-10-01

The concept of a new tree-based architecture for networked multi-player games was proposed by Matuszek to improve scalability in network traffic at the same time to improve reliability. The architecture (we refer it as "Tree-Based Server- Middlemen-Client architecture") will solve the two major problems in ad-hoc wireless networks: frequent link failures and significance in battery power consumption at wireless transceivers by using two new techniques, recursive aggregation of client messages and subscription-based propagation of game state. However, the performance of the TBSMC architecture has never been quantitatively studied. In this paper, the TB-SMC architecture is compared with the client-server architecture using simulation experiments. We developed an event driven simulator to evaluate the performance of the TB-SMC architecture. In the network traffic scalability experiments, the TB-SMC architecture resulted in less than 1/14 of the network traffic load for 200 end users. In the reliability experiments, the TB-SMC architecture improved the number of successfully delivered players' votes by 31.6, 19.0, and 12.4% from the clientserver architecture at high (failure probability of 90%), moderate (50%) and low (10%) failure probability.

A Satellite Data-Driven, Client-Server Decision Support Application for Agricultural Water Resources Management

Science.gov (United States)

Johnson, Lee F.; Maneta, Marco P.; Kimball, John S.

2016-01-01

Water cycle extremes such as droughts and floods present a challenge for water managers and for policy makers responsible for the administration of water supplies in agricultural regions. In addition to the inherent uncertainties associated with forecasting extreme weather events, water planners need to anticipate water demands and water user behavior in a typical circumstances. This requires the use decision support systems capable of simulating agricultural water demand with the latest available data. Unfortunately, managers from local and regional agencies often use different datasets of variable quality, which complicates coordinated action. In previous work we have demonstrated novel methodologies to use satellite-based observational technologies, in conjunction with hydro-economic models and state of the art data assimilation methods, to enable robust regional assessment and prediction of drought impacts on agricultural production, water resources, and land allocation. These methods create an opportunity for new, cost-effective analysis tools to support policy and decision-making over large spatial extents. The methods can be driven with information from existing satellite-derived operational products, such as the Satellite Irrigation Management Support system (SIMS) operational over California, the Cropland Data Layer (CDL), and using a modified light-use efficiency algorithm to retrieve crop yield from the synergistic use of MODIS and Landsat imagery. Here we present an integration of this modeling framework in a client-server architecture based on the Hydra platform. Assimilation and processing of resource intensive remote sensing data, as well as hydrologic and other ancillary information occur on the server side. This information is processed and summarized as attributes in water demand nodes that are part of a vector description of the water distribution network. With this architecture, our decision support system becomes a light weight 'app' that

Markerless client-server augmented reality system with natural features

Science.gov (United States)

Ning, Shuangning; Sang, Xinzhu; Chen, Duo

2017-10-01

A markerless client-server augmented reality system is presented. In this research, the more extensive and mature virtual reality head-mounted display is adopted to assist the implementation of augmented reality. The viewer is provided an image in front of their eyes with the head-mounted display. The front-facing camera is used to capture video signals into the workstation. The generated virtual scene is merged with the outside world information received from the camera. The integrated video is sent to the helmet display system. The distinguishing feature and novelty is to realize the augmented reality with natural features instead of marker, which address the limitations of the marker, such as only black and white, the inapplicability of different environment conditions, and particularly cannot work when the marker is partially blocked. Further, 3D stereoscopic perception of virtual animation model is achieved. The high-speed and stable socket native communication method is adopted for transmission of the key video stream data, which can reduce the calculation burden of the system.

Experimental Blind Quantum Computing for a Classical Client

Science.gov (United States)

Huang, He-Liang; Zhao, Qi; Ma, Xiongfeng; Liu, Chang; Su, Zu-En; Wang, Xi-Lin; Li, Li; Liu, Nai-Le; Sanders, Barry C.; Lu, Chao-Yang; Pan, Jian-Wei

2017-08-01

To date, blind quantum computing demonstrations require clients to have weak quantum devices. Here we implement a proof-of-principle experiment for completely classical clients. Via classically interacting with two quantum servers that share entanglement, the client accomplishes the task of having the number 15 factorized by servers who are denied information about the computation itself. This concealment is accompanied by a verification protocol that tests servers' honesty and correctness. Our demonstration shows the feasibility of completely classical clients and thus is a key milestone towards secure cloud quantum computing.

Experimental Blind Quantum Computing for a Classical Client.

Science.gov (United States)

Huang, He-Liang; Zhao, Qi; Ma, Xiongfeng; Liu, Chang; Su, Zu-En; Wang, Xi-Lin; Li, Li; Liu, Nai-Le; Sanders, Barry C; Lu, Chao-Yang; Pan, Jian-Wei

2017-08-04

To date, blind quantum computing demonstrations require clients to have weak quantum devices. Here we implement a proof-of-principle experiment for completely classical clients. Via classically interacting with two quantum servers that share entanglement, the client accomplishes the task of having the number 15 factorized by servers who are denied information about the computation itself. This concealment is accompanied by a verification protocol that tests servers' honesty and correctness. Our demonstration shows the feasibility of completely classical clients and thus is a key milestone towards secure cloud quantum computing.

Solid waste information and tracking system client-server conversion project management plan

International Nuclear Information System (INIS)

May, D.L.

1998-01-01

This Project Management Plan is the lead planning document governing the proposed conversion of the Solid Waste Information and Tracking System (SWITS) to a client-server architecture. This plan presents the content specified by American National Standards Institute (ANSI)/Institute of Electrical and Electronics Engineers (IEEE) standards for software development, with additional information categories deemed to be necessary to describe the conversion fully. This plan is a living document that will be reviewed on a periodic basis and revised when necessary to reflect changes in baseline design concepts and schedules. This PMP describes the background, planning and management of the SWITS conversion. It does not constitute a statement of product requirements. Requirements and specification documentation needed for the SWITS conversion will be released as supporting documents

Server-Aided Two-Party Computation with Simultaneous Corruption

DEFF Research Database (Denmark)

Cascudo Pueyo, Ignacio; Damgård, Ivan Bjerre; Ranellucci, Samuel

We consider secure two-party computation in the client-server model where there are two adversaries that operate separately but simultaneously, each of them corrupting one of the parties and a restricted subset of servers that they interact with. We model security via the local universal composab......We consider secure two-party computation in the client-server model where there are two adversaries that operate separately but simultaneously, each of them corrupting one of the parties and a restricted subset of servers that they interact with. We model security via the local universal...

NEOS Server 4.0 Administrative Guide

OpenAIRE

Dolan, Elizabeth D.

2001-01-01

The NEOS Server 4.0 provides a general Internet-based client/server as a link between users and software applications. The administrative guide covers the fundamental principals behind the operation of the NEOS Server, installation and trouble-shooting of the Server software, and implementation details of potential interest to a NEOS Server administrator. The guide also discusses making new software applications available through the Server, including areas of concern to remote solver adminis...

Earthquake Early Warning Management based on Client-Server using Primary Wave data from Vibrating Sensor

Science.gov (United States)

Laumal, F. E.; Nope, K. B. N.; Peli, Y. S.

2018-01-01

Early warning is a warning mechanism before an actual incident occurs, can be implemented on natural events such as tsunamis or earthquakes. Earthquakes are classified in tectonic and volcanic types depend on the source and nature. The tremor in the form of energy propagates in all directions as Primary and Secondary waves. Primary wave as initial earthquake vibrations propagates longitudinally, while the secondary wave propagates like as a sinusoidal wave after Primary, destructive and as a real earthquake. To process the primary vibration data captured by the earthquake sensor, a network management required client computer to receives primary data from sensors, authenticate and forward to a server computer to set up an early warning system. With the water propagation concept, a method of early warning system has been determined in which some sensors are located on the same line, sending initial vibrations as primary data on the same scale and the server recommended to the alarm sound as an early warning.

Rancang Bangun Aplikasi Pembayaran Sekolah Menggunakan Java Dan MySQL Berbasis Client Server Di SMA Yos Sudarso Cilacap

OpenAIRE

Usada, Elisa; Isnawati, Anggun Fitrian; Fatimah, Dewi

2010-01-01

SMA Yos Sudarso merupakan salah satu sekolah yang sudah memanfaatkan komputer  untuk menyelesaikan berbagai macam tugas, tetapi pemanfaatannya masih belum maksimal karena ada bagian administrasi yang masih menggunakan metode manual, yaitu pada administrasi pembayaran. Penelitian ini  berusaha membuat sebuah aplikasi client server berteknologi JAVA dan MySQL untuk mengelola data pembayaran sekolah meliputi pembayaran SPP, pembayaran uang gedung serta pembayaran ujian. Metode waterfal...

Deceit: A flexible distributed file system

Science.gov (United States)

Siegel, Alex; Birman, Kenneth; Marzullo, Keith

1989-01-01

Deceit, a distributed file system (DFS) being developed at Cornell, focuses on flexible file semantics in relation to efficiency, scalability, and reliability. Deceit servers are interchangeable and collectively provide the illusion of a single, large server machine to any clients of the Deceit service. Non-volatile replicas of each file are stored on a subset of the file servers. The user is able to set parameters on a file to achieve different levels of availability, performance, and one-copy serializability. Deceit also supports a file version control mechanism. In contrast with many recent DFS efforts, Deceit can behave like a plain Sun Network File System (NFS) server and can be used by any NFS client without modifying any client software. The current Deceit prototype uses the ISIS Distributed Programming Environment for all communication and process group management, an approach that reduces system complexity and increases system robustness.

CORAL Server and CORAL Server Proxy: Scalable Access to Relational Databases from CORAL Applications

CERN Document Server

Valassi, A; Kalkhof, A; Salnikov, A; Wache, M

2011-01-01

The CORAL software is widely used at CERN for accessing the data stored by the LHC experiments using relational database technologies. CORAL provides a C++ abstraction layer that supports data persistency for several backends and deployment models, including local access to SQLite files, direct client access to Oracle and MySQL servers, and read-only access to Oracle through the FroNTier web server and cache. Two new components have recently been added to CORAL to implement a model involving a middle tier "CORAL server" deployed close to the database and a tree of "CORAL server proxy" instances, with data caching and multiplexing functionalities, deployed close to the client. The new components are meant to provide advantages for read-only and read-write data access, in both offline and online use cases, in the areas of scalability and performance (multiplexing for several incoming connections, optional data caching) and security (authentication via proxy certificates). A first implementation of the two new c...

Using ‘search transitions’ to study searchers investment of effort: experiences with client and server side logging

OpenAIRE

Pharo, Nils; Nordlie, Ragnar

2013-01-01

We are investigating the value of using the concept ‘search transition’ for studying effort invested in information search processes. In this paper we present findings from a comparative study of data collected from client and server side loggings. The purpose is to see what factors of effort can be captured from the two logging methods. The data stems from studies of searchers interaction with an XML information retrieval system. The searchers interaction was simultaneously logged by a scree...

Design and implementation of an enterprise information system utilizing a component based three-tier client/server database system

OpenAIRE

Akbay, Murat.; Lewis, Steven C.

1999-01-01

The Naval Security Group currently requires a modem architecture to merge existing command databases into a single Enterprise Information System through which each command may manipulate administrative data. There are numerous technologies available to build and implement such a system. Component- based architectures are extremely well-suited for creating scalable and flexible three-tier Client/Server systems because the data and business logic are encapsulated within objects, allowing them t...

Towards Big Earth Data Analytics: The EarthServer Approach

Science.gov (United States)

Baumann, Peter

2013-04-01

Big Data in the Earth sciences, the Tera- to Exabyte archives, mostly are made up from coverage data whereby the term "coverage", according to ISO and OGC, is defined as the digital representation of some space-time varying phenomenon. Common examples include 1-D sensor timeseries, 2-D remote sensing imagery, 3D x/y/t image timeseries and x/y/z geology data, and 4-D x/y/z/t atmosphere and ocean data. Analytics on such data requires on-demand processing of sometimes significant complexity, such as getting the Fourier transform of satellite images. As network bandwidth limits prohibit transfer of such Big Data it is indispensable to devise protocols allowing clients to task flexible and fast processing on the server. The EarthServer initiative, funded by EU FP7 eInfrastructures, unites 11 partners from computer and earth sciences to establish Big Earth Data Analytics. One key ingredient is flexibility for users to ask what they want, not impeded and complicated by system internals. The EarthServer answer to this is to use high-level query languages; these have proven tremendously successful on tabular and XML data, and we extend them with a central geo data structure, multi-dimensional arrays. A second key ingredient is scalability. Without any doubt, scalability ultimately can only be achieved through parallelization. In the past, parallelizing code has been done at compile time and usually with manual intervention. The EarthServer approach is to perform a samentic-based dynamic distribution of queries fragments based on networks optimization and further criteria. The EarthServer platform is comprised by rasdaman, an Array DBMS enabling efficient storage and retrieval of any-size, any-type multi-dimensional raster data. In the project, rasdaman is being extended with several functionality and scalability features, including: support for irregular grids and general meshes; in-situ retrieval (evaluation of database queries on existing archive structures, avoiding data

CheD: chemical database compilation tool, Internet server, and client for SQL servers.

Science.gov (United States)

Trepalin, S V; Yarkov, A V

2001-01-01

An efficient program, which runs on a personal computer, for the storage, retrieval, and processing of chemical information, is presented, The program can work both as a stand-alone application or in conjunction with a specifically written Web server application or with some standard SQL servers, e.g., Oracle, Interbase, and MS SQL. New types of data fields are introduced, e.g., arrays for spectral information storage, HTML and database links, and user-defined functions. CheD has an open architecture; thus, custom data types, controls, and services may be added. A WWW server application for chemical data retrieval features an easy and user-friendly installation on Windows NT or 95 platforms.

Distributed Digital Survey Logbook Built on GeoServer and PostGIS

Science.gov (United States)

Jovicic, Aleksandar; Castelli, Ana; Kljajic, Zoran

2013-04-01

Keeping tracks of events that happens during survey (e.g. position and time when instruments goes into the water or come on-board, depths from which samples are taken or notes about equipment malfunctions and repairs) is essential for efficient post-processing and quality control of collected data especially in case of suspicious measurements. Most scientists still using good-old-paper way for such tasks and later transform it into digital form using spreadsheet applications. This approach looks more "safe" (if person is not confident in their computer skills) but in reality it turns to be more error-prone (especially when it comes to position recording and variations of sexagesimal representations or if there are no hints which timezone was used for time recording). As cruises usually involves various teams not always interested to do own measurements at each station, keeping eye on current position is essential, especially if cruise plan is changed (due to bad weather or discovering of some underwater features that requires more attention than originally planned). Also, position is usually displayed only at one monitor (as most GPS receivers provide just serial connectivity and distribution of such signal to multiple clients requires some devices non-wide-spread on computer equipment market) so it can make messy situation in control room when everybody try to write-down current position and time. To overcome all mentioned obstacles Distributed Digital Surevey Logbook is implemented. It is built on Open Geospatial Consortium (OGC) compliant GeoServer, using PostGIS database. It can handle geospatial content (charts and cruise plans), do recording of vessel track and all kind of events that any member of team want to record. As GeoServer allows distribution of position data to unlimited number of clients (from traditional PC's and laptops to tablets and smartphones), it can decrease pressure on control room no matter if all features are used or just as distant

Windows Home Server users guide

CERN Document Server

Edney, Andrew

2008-01-01

Windows Home Server brings the idea of centralized storage, backup and computer management out of the enterprise and into the home. Windows Home Server is built for people with multiple computers at home and helps to synchronize them, keep them updated, stream media between them, and back them up centrally. Built on a similar foundation as the Microsoft server operating products, it's essentially Small Business Server for the home.This book details how to install, configure, and use Windows Home Server and explains how to connect to and manage different clients such as Windows XP, Windows Vist

Locating Nearby Copies of Replicated Internet Servers

National Research Council Canada - National Science Library

Guyton, James D; Schwartz, Michael F

1995-01-01

In this paper we consider the problem of choosing among a collection of replicated servers focusing on the question of how to make choices that segregate client/server traffic according to network topology...

A satellite-driven, client-server hydro-economic model prototype for agricultural water management

Science.gov (United States)

Maneta, Marco; Kimball, John; He, Mingzhu; Payton Gardner, W.

2017-04-01

Anticipating agricultural water demand, land reallocation, and impact on farm revenues associated with different policy or climate constraints is a challenge for water managers and for policy makers. While current integrated decision support systems based on programming methods provide estimates of farmer reaction to external constraints, they have important shortcomings such as the high cost of data collection surveys necessary to calibrate the model, biases associated with inadequate farm sampling, infrequent model updates and recalibration, model overfitting, or their deterministic nature, among other problems. In addition, the administration of water supplies and the generation of policies that promote sustainable agricultural regions depend on more than one bureau or office. Unfortunately, managers from local and regional agencies often use different datasets of variable quality, which complicates coordinated action. To overcome these limitations, we present a client-server, integrated hydro-economic modeling and observation framework driven by satellite remote sensing and other ancillary information from regional monitoring networks. The core of the framework is a stochastic data assimilation system that sequentially ingests remote sensing observations and corrects the parameters of the hydro-economic model at unprecedented spatial and temporal resolutions. An economic model of agricultural production, based on mathematical programming, requires information on crop type and extent, crop yield, crop transpiration and irrigation technology. A regional hydro-climatologic model provides biophysical constraints to an economic model of agricultural production with a level of detail that permits the study of the spatial impact of large- and small-scale water use decisions. Crop type and extent is obtained from the Cropland Data Layer (CDL), which is multi-sensor operational classification of crops maintained by the United States Department of Agriculture. Because

Exam 70-411 administering Windows Server 2012

CERN Document Server

Course, Microsoft Official Academic

2014-01-01

Microsoft Windows Server is a multi-purpose server designed to increase reliability and flexibility of  a network infrastructure. Windows Server is the paramount tool used by enterprises in their datacenter and desktop strategy. The most recent versions of Windows Server also provide both server and client virtualization. Its ubiquity in the enterprise results in the need for networking professionals who know how to plan, design, implement, operate, and troubleshoot networks relying on Windows Server. Microsoft Learning is preparing the next round of its Windows Server Certification program

The HydroServer Platform for Sharing Hydrologic Data

Science.gov (United States)

Tarboton, D. G.; Horsburgh, J. S.; Schreuders, K.; Maidment, D. R.; Zaslavsky, I.; Valentine, D. W.

2010-12-01

The CUAHSI Hydrologic Information System (HIS) is an internet based system that supports sharing of hydrologic data. HIS consists of databases connected using the Internet through Web services, as well as software for data discovery, access, and publication. The HIS system architecture is comprised of servers for publishing and sharing data, a centralized catalog to support cross server data discovery and a desktop client to access and analyze data. This paper focuses on HydroServer, the component developed for sharing and publishing space-time hydrologic datasets. A HydroServer is a computer server that contains a collection of databases, web services, tools, and software applications that allow data producers to store, publish, and manage the data from an experimental watershed or project site. HydroServer is designed to permit publication of data as part of a distributed national/international system, while still locally managing access to the data. We describe the HydroServer architecture and software stack, including tools for managing and publishing time series data for fixed point monitoring sites as well as spatially distributed, GIS datasets that describe a particular study area, watershed, or region. HydroServer adopts a standards based approach to data publication, relying on accepted and emerging standards for data storage and transfer. CUAHSI developed HydroServer code is free with community code development managed through the codeplex open source code repository and development system. There is some reliance on widely used commercial software for general purpose and standard data publication capability. The sharing of data in a common format is one way to stimulate interdisciplinary research and collaboration. It is anticipated that the growing, distributed network of HydroServers will facilitate cross-site comparisons and large scale studies that synthesize information from diverse settings, making the network as a whole greater than the sum of its

Migration of the CNA maintenance information system to a client server architecture

International Nuclear Information System (INIS)

Gonzalez Crego, E.; Martin Lopez-Suevos, C.

1994-01-01

The paper explains the guidelines and methodology followed to carry out regulation of the CNA computerized maintenance system (SIGE) to a system with a client/server architecture based on ORACLE. The following guidelines were established to carry out migration: 1 Ensure that the new system would contain all the information of the former system, ie, no information would be lost during migration. 2 Improve the technical design of the application, while maintaining at least the functionality of the former application 3 incorporate modifications into the application which would permit incremental improvement of its functionality. 4 Carry out migration at the minimum cost in time and resources to construct the application, a strict development methodology was followed and certain standards were drawn up to significantly increase the speed. Special use was made of: 1 Data models 2 Process models which operate the data model 3 SQL-FORMS standards 4 Safety features

New distributive web-caching technique for VOD services

Science.gov (United States)

Kim, Iksoo; Woo, Yoseop; Hwang, Taejune; Choi, Jintak; Kim, Youngjune

2002-12-01

At present, one of the most popular services through internet is on-demand services including VOD, EOD and NOD. But the main problems for on-demand service are excessive load of server and insufficiency of network resources. Therefore the service providers require a powerful expensive server and clients are faced with long end-to-end delay and network congestion problem. This paper presents a new distributive web-caching technique for fluent VOD services using distributed proxies in Head-end-Network (HNET). The HNET consists of a Switching-Agent (SA) as a control node, some Head-end Nodes (HEN) as proxies and clients connected to HEN. And each HEN is composing a LAN. Clients request VOD services to server through a HEN and SA. The SA operates the heart of HNET, all the operations using proposed distributive caching technique perform under the control of SA. This technique stores some parts of a requested video on the corresponding HENs when clients connected to each HEN request an identical video. Thus, clients access those HENs (proxies) alternatively for acquiring video streams. Eventually, this fact leads to equi-loaded proxy (HEN). We adopt the cache replacement strategy using the combination of LRU, LFU, remove streams from other HEN prior to server streams and the method of replacing the first block of video last to reduce end-to end delay.

Enforcing Resource Sharing Agreements Among Distributed Server Clusters

National Research Council Canada - National Science Library

Zhao, Tao; Karamcheti, Vijay

2001-01-01

Future scalable, high throughput, and high performance applications are likely to execute on platforms constructed by clustering multiple autonomous distributed servers, with resource access governed...

Multi-server blind quantum computation over collective-noise channels

Science.gov (United States)

Xiao, Min; Liu, Lin; Song, Xiuli

2018-03-01

Blind quantum computation (BQC) enables ordinary clients to securely outsource their computation task to costly quantum servers. Besides two essential properties, namely correctness and blindness, practical BQC protocols also should make clients as classical as possible and tolerate faults from nonideal quantum channel. In this paper, using logical Bell states as quantum resource, we propose multi-server BQC protocols over collective-dephasing noise channel and collective-rotation noise channel, respectively. The proposed protocols permit completely or almost classical client, meet the correctness and blindness requirements of BQC protocol, and are typically practical BQC protocols.

Distributed PACS using distributed file system with hierarchical meta data servers.

Science.gov (United States)

Hiroyasu, Tomoyuki; Minamitani, Yoshiyuki; Miki, Mitsunori; Yokouchi, Hisatake; Yoshimi, Masato

2012-01-01

In this research, we propose a new distributed PACS (Picture Archiving and Communication Systems) which is available to integrate several PACSs that exist in each medical institution. The conventional PACS controls DICOM file into one data-base. On the other hand, in the proposed system, DICOM file is separated into meta data and image data and those are stored individually. Using this mechanism, since file is not always accessed the entire data, some operations such as finding files, changing titles, and so on can be performed in high-speed. At the same time, as distributed file system is utilized, accessing image files can also achieve high-speed access and high fault tolerant. The introduced system has a more significant point. That is the simplicity to integrate several PACSs. In the proposed system, only the meta data servers are integrated and integrated system can be constructed. This system also has the scalability of file access with along to the number of file numbers and file sizes. On the other hand, because meta-data server is integrated, the meta data server is the weakness of this system. To solve this defect, hieratical meta data servers are introduced. Because of this mechanism, not only fault--tolerant ability is increased but scalability of file access is also increased. To discuss the proposed system, the prototype system using Gfarm was implemented. For evaluating the implemented system, file search operating time of Gfarm and NFS were compared.

Dynamic Server-Based KML Code Generator Method for Level-of-Detail Traversal of Geospatial Data

Science.gov (United States)

Baxes, Gregory; Mixon, Brian; Linger, TIm

2013-01-01

Web-based geospatial client applications such as Google Earth and NASA World Wind must listen to data requests, access appropriate stored data, and compile a data response to the requesting client application. This process occurs repeatedly to support multiple client requests and application instances. Newer Web-based geospatial clients also provide user-interactive functionality that is dependent on fast and efficient server responses. With massively large datasets, server-client interaction can become severely impeded because the server must determine the best way to assemble data to meet the client applications request. In client applications such as Google Earth, the user interactively wanders through the data using visually guided panning and zooming actions. With these actions, the client application is continually issuing data requests to the server without knowledge of the server s data structure or extraction/assembly paradigm. A method for efficiently controlling the networked access of a Web-based geospatial browser to server-based datasets in particular, massively sized datasets has been developed. The method specifically uses the Keyhole Markup Language (KML), an Open Geospatial Consortium (OGS) standard used by Google Earth and other KML-compliant geospatial client applications. The innovation is based on establishing a dynamic cascading KML strategy that is initiated by a KML launch file provided by a data server host to a Google Earth or similar KMLcompliant geospatial client application user. Upon execution, the launch KML code issues a request for image data covering an initial geographic region. The server responds with the requested data along with subsequent dynamically generated KML code that directs the client application to make follow-on requests for higher level of detail (LOD) imagery to replace the initial imagery as the user navigates into the dataset. The approach provides an efficient data traversal path and mechanism that can be

EarthServer: a Summary of Achievements in Technology, Services, and Standards

Science.gov (United States)

Baumann, Peter

2015-04-01

Big Data in the Earth sciences, the Tera- to Exabyte archives, mostly are made up from coverage data, according to ISO and OGC defined as the digital representation of some space-time varying phenomenon. Common examples include 1-D sensor timeseries, 2-D remote sensing imagery, 3D x/y/t image timese ries and x/y/z geology data, and 4-D x/y/z/t atmosphere and ocean data. Analytics on such data requires on-demand processing of sometimes significant complexity, such as getting the Fourier transform of satellite images. As network bandwidth limits prohibit transfer of such Big Data it is indispensable to devise protocols allowing clients to task flexible and fast processing on the server. The transatlantic EarthServer initiative, running from 2011 through 2014, has united 11 partners to establish Big Earth Data Analytics. A key ingredient has been flexibility for users to ask whatever they want, not impeded and complicated by system internals. The EarthServer answer to this is to use high-level, standards-based query languages which unify data and metadata search in a simple, yet powerful way. A second key ingredient is scalability. Without any doubt, scalability ultimately can only be achieved through parallelization. In the past, parallelizing cod e has been done at compile time and usually with manual intervention. The EarthServer approach is to perform a samentic-based dynamic distribution of queries fragments based on networks optimization and further criteria. The EarthServer platform is comprised by rasdaman, the pioneer and leading Array DBMS built for any-size multi-dimensional raster data being extended with support for irregular grids and general meshes; in-situ retrieval (evaluation of database queries on existing archive structures, avoiding data import and, hence, duplication); the aforementioned distributed query processing. Additionally, Web clients for multi-dimensional data visualization are being established. Client/server interfaces are strictly

RANCANG BANGUN PERANGKAT LUNAK MANAJEMEN DATABASE SQL SERVER BERBASIS WEB

Directory of Open Access Journals (Sweden)

Muchammad Husni

2005-01-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Microsoft SQL Server merupakan aplikasi desktop database server yang bersifat client/server, karena memiliki komponen client, yang  berfungsi menampilkan dan memanipulasi data; serta komponen server yang berfungsi menyimpan, memanggil, dan mengamankan database. Operasi-operasi manajemen semua server database dalam jaringan dilakukan administrator database dengan menggunakan tool administratif utama SQL Server yang bernama Enterprise Manager. Hal ini mengakibatkan administrator database hanya bisa  melakukan operasi-operasi tersebut di komputer yang telah diinstalasi Microsoft SQL Server. Pada penelitian ini, dirancang suatu aplikasi berbasis web dengan menggunakan ASP.Net untuk melakukan pengaturan database server. Aplikasi ini menggunakan ADO.NET yang memanfaatkan Transact-SQL dan stored procedure pada server untuk melakukan operasi-operasi manajemen database pada suatu server database SQL, dan menampilkannya ke dalam web. Administrator database bisa menjalankan aplikasi berbasis web tersebut dari komputer mana saja pada jaringan dan melakukan koneksi ke server database SQL dengan menggunakan web browser. Dengan demikian memudahkan administrator melakukan tugasnya tanpa harus menggunakan komputer server.   Kata Kunci : Transact-SQL, ASP.Net, ADO.NET, SQL Server

Network characteristics for server selection in online games

Science.gov (United States)

Claypool, Mark

2008-01-01

Online gameplay is impacted by the network characteristics of players connected to the same server. Unfortunately, the network characteristics of online game servers are not well-understood, particularly for groups that wish to play together on the same server. As a step towards a remedy, this paper presents analysis of an extensive set of measurements of game servers on the Internet. Over the course of many months, actual Internet game servers were queried simultaneously by twenty-five emulated game clients, with both servers and clients spread out on the Internet. The data provides statistics on the uptime and populations of game servers over a month long period an an in-depth look at the suitability for game servers for multi-player server selection, concentrating on characteristics critical to playability--latency and fairness. Analysis finds most game servers have latencies suitable for third-person and omnipresent games, such as real-time strategy, sports and role-playing games, providing numerous server choices for game players. However, far fewer game servers have the low latencies required for first-person games, such as shooters or race games. In all cases, groups that wish to play together have a greatly reduced set of servers from which to choose because of inherent unfairness in server latencies and server selection is particularly limited as the group size increases. These results hold across different game types and even across different generations of games. The data should be useful for game developers and network researchers that seek to improve game server selection, whether for single or multiple players.

Moving the Hazard Prediction and Assessment Capability to a Distributed, Portable Architecture

Energy Technology Data Exchange (ETDEWEB)

Lee, RW

2002-09-05

The Hazard Prediction and Assessment Capability (HPAC) has been re-engineered from a Windows application with tight binding between computation and a graphical user interface (GUI) to a new distributed object architecture. The key goals of this new architecture are platform portability, extensibility, deployment flexibility, client-server operations, easy integration with other systems, and support for a new map-based GUI. Selection of Java as the development and runtime environment is the major factor in achieving each of the goals, platform portability in particular. Portability is further enforced by allowing only Java components in the client. Extensibility is achieved via Java's dynamic binding and class loading capabilities and a design by interface approach. HPAC supports deployment on a standalone host, as a heavy client in client-server mode with data stored on the client but calculations performed on the server host, and as a thin client with data and calculations on the server host. The principle architectural element supporting deployment flexibility is the use of Universal Resource Locators (URLs) for all file references. Java WebStart{trademark} is used for thin client deployment. Although there were many choices for the object distribution mechanism, the Common Object Request Broker Architecture (CORBA) was chosen to support HPAC client server operation. HPAC complies with version 2.0 of the CORBA standard and does not assume support for pass-by-value method arguments. Execution in standalone mode is expedited by having most server objects run in the same process as client objects, thereby bypassing CORBA object transport. HPAC provides four levels for access by other tools and systems, starting with a Windows library providing transport and dispersion (T&D) calculations and output generation, detailed and more abstract sets of CORBA services, and reusable Java components.

The SAMGrid database server component: its upgraded infrastructure and future development path

International Nuclear Information System (INIS)

Loebel-Carpenter, L.; White, S.; Baranovski, A.; Garzoglio, G.; Herber, R.; Illingworth, R.; Kennedy, R.; Kreymer, A.; Kumar, A.; Lueking, L.; Lyon, A.; Merritt, W.; Terekhov, I.; Trumbo, J.; Veseli, S.; Burgon-Lyon, M.; St Denis, R.; Belforte, S.; Kerzel, U.; Bartsch, V.; Leslie, M.

2004-01-01

The SAMGrid Database Server encapsulates several important services, such as accessing file metadata and replica catalog, keeping track of the processing information, as well as providing the runtime support for SAMGrid station services. Recent deployment of the SAMGrid system for CDF has resulted in unification of the database schema used by CDF and D0, and the complexity of changes required for the unified metadata catalog has warranted a complete redesign of the DB Server. We describe here the architecture and features of the new server. In particular, we discuss the new CORBA infrastructure that utilizes python wrapper classes around IDL structs and exceptions. Such infrastructure allows us to use the same code on both server and client sides, which in turn results in significantly improved code maintainability and easier development. We also discuss future integration of the new server with an SBIR II project which is directed toward allowing the DB Server to access distributed databases, implemented in different DB systems and possibly using different schema

The design of distributed database system for HIRFL

International Nuclear Information System (INIS)

Wang Hong; Huang Xinmin

2004-01-01

This paper is focused on a kind of distributed database system used in HIRFL distributed control system. The database of this distributed database system is established by SQL Server 2000, and its application system adopts the Client/Server model. Visual C ++ is used to develop the applications, and the application uses ODBC to access the database. (authors)

Server Interface Descriptions for Automated Testing of JavaScript Web Applications

DEFF Research Database (Denmark)

Jensen, Casper Svenning; Møller, Anders; Su, Zhendong

2013-01-01

Automated testing of JavaScript web applications is complicated by the communication with servers. Specifically, it is difficult to test the JavaScript code in isolation from the server code and database contents. We present a practical solution to this problem. First, we demonstrate that formal...... server interface descriptions are useful in automated testing of JavaScript web applications for separating the concerns of the client and the server. Second, to support the construction of server interface descriptions for existing applications, we introduce an effective inference technique that learns...... communication patterns from sample data. By incorporating interface descriptions into the testing tool Artemis, our experimental results show that we increase the level of automation for high-coverage testing on a collection of JavaScript web applications that exchange JSON data between the clients and servers...

Conflict free network coding for distributed storage networks

KAUST Repository

Al-Habob, Ahmed A.; Sorour, Sameh; Aboutorab, Neda; Sadeghi, Parastoo

2015-01-01

© 2015 IEEE. In this paper, we design a conflict free instantly decodable network coding (IDNC) solution for file download from distributed storage servers. Considering previously downloaded files at the clients from these servers as side

Efficient Incremental Garbage Collection for Workstation/Server Database Systems

OpenAIRE

Amsaleg , Laurent; Gruber , Olivier; Franklin , Michael

1994-01-01

Projet RODIN; We describe an efficient server-based algorithm for garbage collecting object-oriented databases in a workstation/server environment. The algorithm is incremental and runs concurrently with client transactions, however, it does not hold any locks on data and does not require callbacks to clients. It is fault tolerant, but performs very little logging. The algorithm has been designed to be integrated into existing OODB systems, and therefore it works with standard implementation ...

Efficient Mobile Client Caching Supporting Transaction Semantics

Directory of Open Access Journals (Sweden)

IlYoung Chung

2000-05-01

Full Text Available In mobile client-server database systems, caching of frequently accessed data is an important technique that will reduce the contention on the narrow bandwidth wireless channel. As the server in mobile environments may not have any information about the state of its clients' cache(stateless server, using broadcasting approach to transmit the updated data lists to numerous concurrent mobile clients is an attractive approach. In this paper, a caching policy is proposed to maintain cache consistency for mobile computers. The proposed protocol adopts asynchronous(non-periodic broadcasting as the cache invalidation scheme, and supports transaction semantics in mobile environments. With the asynchronous broadcasting approach, the proposed protocol can improve the throughput by reducing the abortion of transactions with low communication costs. We study the performance of the protocol by means of simulation experiments.

WPS-based technology for client-side remote sensing data processing

Science.gov (United States)

Kazakov, E.; Terekhov, A.; Kapralov, E.; Panidi, E.

2015-04-01

Server-side processing is principal for most of the current Web-based geospatial data processing tools. However, in some cases the client-side geoprocessing may be more convenient and acceptable. This study is dedicated to the development of methodology and techniques of Web services elaboration, which allow the client-side geoprocessing also. The practical objectives of the research are focused on the remote sensing data processing, which are one of the most resource-intensive data types. The idea underlying the study is to propose such geoprocessing Web service schema that will be compatible with the current serveroriented Open Geospatial Consortium standard (OGC WPS standard), and additionally will allow to run the processing on the client, transmitting processing tool (executable code) over the network instead of the data. At the same time, the unity of executable code must be preserved, and the transmitted code should be the same to that is used for server-side processing. This unity should provide unconditional identity of the processing results that performed using of any schema. The appropriate services are pointed by the authors as a Hybrid Geoprocessing Web Services (HGWSs). The common approaches to architecture and structure of the HGWSs are proposed at the current stage as like as a number of service prototypes. For the testing of selected approaches, the geoportal prototype was implemented, which provides access to created HGWS. Further works are conducted on the formalization of platform independent HGWSs implementation techniques, and on the approaches to conceptualization of theirs safe use and chaining possibilities. The proposed schema of HGWSs implementation could become one of the possible solutions for the distributed systems, assuming that the processing servers could play the role of the clients connecting to the service supply server. The study was partially supported by Russian Foundation for Basic Research (RFBR), research project No. 13

A Heterogeneous Distributed Virtual Geographic Environment—Potential Application in Spatiotemporal Behavior Experiments

Directory of Open Access Journals (Sweden)

Shen Shen

2018-02-01

Full Text Available Due to their strong immersion and real-time interactivity, helmet-mounted virtual reality (VR devices are becoming increasingly popular. Based on these devices, an immersive virtual geographic environment (VGE provides a promising method for research into crowd behavior in an emergency. However, the current cheaper helmet-mounted VR devices are not popular enough, and will continue to coexist with personal computer (PC-based systems for a long time. Therefore, a heterogeneous distributed virtual geographic environment (HDVGE could be a feasible solution to the heterogeneous problems caused by various types of clients, and support the implementation of spatiotemporal crowd behavior experiments with large numbers of concurrent participants. In this study, we developed an HDVGE framework, and put forward a set of design principles to define the similarities between the real world and the VGE. We discussed the HDVGE architecture, and proposed an abstract interaction layer, a protocol-based interaction algorithm, and an adjusted dead reckoning algorithm to solve the heterogeneous distributed problems. We then implemented an HDVGE prototype system focusing on subway fire evacuation experiments. Two types of clients are considered in the system: PC, and all-in-one VR. Finally, we evaluated the performances of the prototype system and the key algorithms. The results showed that in a low-latency local area network (LAN environment, the prototype system can smoothly support 90 concurrent users consisting of PC and all-in-one VR clients. HDVGE provides a feasible solution for studying not only spatiotemporal crowd behaviors in normal conditions, but also evacuation behaviors in emergency conditions such as fires and earthquakes. HDVGE could also serve as a new means of obtaining observational data about individual and group behavior in support of human geography research.

Vacation model for Markov machine repair problem with two heterogeneous unreliable servers and threshold recovery

Science.gov (United States)

Jain, Madhu; Meena, Rakesh Kumar

2018-03-01

Markov model of multi-component machining system comprising two unreliable heterogeneous servers and mixed type of standby support has been studied. The repair job of broken down machines is done on the basis of bi-level threshold policy for the activation of the servers. The server returns back to render repair job when the pre-specified workload of failed machines is build up. The first (second) repairman turns on only when the work load of N1 (N2) failed machines is accumulated in the system. The both servers may go for vacation in case when all the machines are in good condition and there are no pending repair jobs for the repairmen. Runge-Kutta method is implemented to solve the set of governing equations used to formulate the Markov model. Various system metrics including the mean queue length, machine availability, throughput, etc., are derived to determine the performance of the machining system. To provide the computational tractability of the present investigation, a numerical illustration is provided. A cost function is also constructed to determine the optimal repair rate of the server by minimizing the expected cost incurred on the system. The hybrid soft computing method is considered to develop the adaptive neuro-fuzzy inference system (ANFIS). The validation of the numerical results obtained by Runge-Kutta approach is also facilitated by computational results generated by ANFIS.

Justifying the need for forensically ready protocols: A case study of identifying malicious web servers using client honeypots

Energy Technology Data Exchange (ETDEWEB)

Seifert, Christian; Endicott-Popovsky, Barbara E.; Frincke, Deborah A.; Komisarczuk, Peter; Muschevici, Radu; Welch, Ian D.

2008-01-03

Abstract: Client honeypot technology can find malicious web servers that attack web browsers and push malware, so called drive-by-downloads, to the client machine. Merely recording the network traffic is insufficient to perform an efficient forensic analysis of the attack. Custom tools need to be developed to access and examine the embedded data of the network protocols. Once the information is extracted from the network data, it cannot be used to perform a behavioral analysis on the attack, therefore limiting the ability to answer what exactly happened on the attacked system. Implementation of a record/ replay mechanism is proposed that allows the forensic examiner to easily extract application data from recorded network streams and allows applications to interact with such data for behavioral analysis purposes. A concrete implementation of such a setup for HTTP and DNS protocols using the HTTP proxy Squid and DNS proxy pdnsd is presented and its effect on digital forensic analysis demonstrated.

Mastering Microsoft Windows Server 2008 R2

CERN Document Server

Minasi, Mark; Finn, Aidan

2010-01-01

The one book you absolutely need to get up and running with Windows Server 2008 R2. One of the world's leading Windows authorities and top-selling author Mark Minasi explores every nook and cranny of the latest version of Microsoft's flagship network operating system, Windows Server 2008 R2, giving you the most in-depth coverage in any book on the market.: Focuses on Windows Windows Server 2008 R2, the newest version of Microsoft's Windows' server line of operating system, and the ideal server for new Windows 7 clients; Author Mark Minasi is one of the world's leading Windows authorities and h

NCI's Distributed Geospatial Data Server

Science.gov (United States)

Larraondo, P. R.; Evans, B. J. K.; Antony, J.

2016-12-01

Earth systems, environmental and geophysics datasets are an extremely valuable source of information about the state and evolution of the Earth. However, different disciplines and applications require this data to be post-processed in different ways before it can be used. For researchers experimenting with algorithms across large datasets or combining multiple data sets, the traditional approach to batch data processing and storing all the output for later analysis rapidly becomes unfeasible, and often requires additional work to publish for others to use. Recent developments on distributed computing using interactive access to significant cloud infrastructure opens the door for new ways of processing data on demand, hence alleviating the need for storage space for each individual copy of each product. The Australian National Computational Infrastructure (NCI) has developed a highly distributed geospatial data server which supports interactive processing of large geospatial data products, including satellite Earth Observation data and global model data, using flexible user-defined functions. This system dynamically and efficiently distributes the required computations among cloud nodes and thus provides a scalable analysis capability. In many cases this completely alleviates the need to preprocess and store the data as products. This system presents a standards-compliant interface, allowing ready accessibility for users of the data. Typical data wrangling problems such as handling different file formats and data types, or harmonising the coordinate projections or temporal and spatial resolutions, can now be handled automatically by this service. The geospatial data server exposes functionality for specifying how the data should be aggregated and transformed. The resulting products can be served using several standards such as the Open Geospatial Consortium's (OGC) Web Map Service (WMS) or Web Feature Service (WFS), Open Street Map tiles, or raw binary arrays under

A Secured Load Mitigation and Distribution Scheme for Securing SIP Server

Directory of Open Access Journals (Sweden)

Vennila Ganesan

2017-01-01

Full Text Available Managing the performance of the Session Initiation Protocol (SIP server under heavy load conditions is a critical task in a Voice over Internet Protocol (VoIP network. In this paper, a two-tier model is proposed for the security, load mitigation, and distribution issues of the SIP server. In the first tier, the proposed handler segregates and drops the malicious traffic. The second tier provides a uniform load of distribution, using the least session termination time (LSTT algorithm. Besides, the mean session termination time is minimized by reducing the waiting time of the SIP messages. Efficiency of the LSTT algorithm is evaluated through the experimental test bed by considering with and without a handler. The experimental results establish that the proposed two-tier model improves the throughput and the CPU utilization. It also reduces the response time and error rate while preserving the quality of multimedia session delivery. This two-tier model provides robust security, dynamic load distribution, appropriate server selection, and session synchronization.

DelPhi web server v2: incorporating atomic-style geometrical figures into the computational protocol.

Science.gov (United States)

Smith, Nicholas; Witham, Shawn; Sarkar, Subhra; Zhang, Jie; Li, Lin; Li, Chuan; Alexov, Emil

2012-06-15

A new edition of the DelPhi web server, DelPhi web server v2, is released to include atomic presentation of geometrical figures. These geometrical objects can be used to model nano-size objects together with real biological macromolecules. The position and size of the object can be manipulated by the user in real time until desired results are achieved. The server fixes structural defects, adds hydrogen atoms and calculates electrostatic energies and the corresponding electrostatic potential and ionic distributions. The web server follows a client-server architecture built on PHP and HTML and utilizes DelPhi software. The computation is carried out on supercomputer cluster and results are given back to the user via http protocol, including the ability to visualize the structure and corresponding electrostatic potential via Jmol implementation. The DelPhi web server is available from http://compbio.clemson.edu/delphi_webserver.

Adventures in the evolution of a high-bandwidth network for central servers

International Nuclear Information System (INIS)

Swartz, K.L.; Cottrell, L.; Dart, M.

1994-08-01

In a small network, clients and servers may all be connected to a single Ethernet without significant performance concerns. As the number of clients on a network grows, the necessity of splitting the network into multiple sub-networks, each with a manageable number of clients, becomes clear. Less obvious is what to do with the servers. Group file servers on subnets and multihomed servers offer only partial solutions -- many other types of servers do not lend themselves to a decentralized model, and tend to collect on another, well-connected but overloaded Ethernet. The higher speed of FDDI seems to offer an easy solution, but in practice both expense and interoperability problems render FDDI a poor choice. Ethernet switches appear to permit cheaper and more reliable networking to the servers while providing an aggregate network bandwidth greater than a simple Ethernet. This paper studies the evolution of the server networks at SLAC. Difficulties encountered in the deployment of FDDI are described, as are the tools and techniques used to characterize the traffic patterns on the server network. Performance of Ethernet, FDDI, and switched Ethernet networks is analyzed, as are reliability and maintainability issues for these alternatives. The motivations for re-designing the SLAC general server network to use a switched Ethernet instead of FDDI are described, as are the reasons for choosing FDDI for the farm and firewall networks at SLAC. Guidelines are developed which may help in making this choice for other networks

Development of Virtual Resource Based IoT Proxy for Bridging Heterogeneous Web Services in IoT Networks

Directory of Open Access Journals (Sweden)

Wenquan Jin

2018-05-01

Full Text Available The Internet of Things is comprised of heterogeneous devices, applications, and platforms using multiple communication technologies to connect the Internet for providing seamless services ubiquitously. With the requirement of developing Internet of Things products, many protocols, program libraries, frameworks, and standard specifications have been proposed. Therefore, providing a consistent interface to access services from those environments is difficult. Moreover, bridging the existing web services to sensor and actuator networks is also important for providing Internet of Things services in various industry domains. In this paper, an Internet of Things proxy is proposed that is based on virtual resources to bridge heterogeneous web services from the Internet to the Internet of Things network. The proxy enables clients to have transparent access to Internet of Things devices and web services in the network. The proxy is comprised of server and client to forward messages for different communication environments using the virtual resources which include the server for the message sender and the client for the message receiver. We design the proxy for the Open Connectivity Foundation network where the virtual resources are discovered by the clients as Open Connectivity Foundation resources. The virtual resources represent the resources which expose services in the Internet by web service providers. Although the services are provided by web service providers from the Internet, the client can access services using the consistent communication protocol in the Open Connectivity Foundation network. For discovering the resources to access services, the client also uses the consistent discovery interface to discover the Open Connectivity Foundation devices and virtual resources.

Development of Virtual Resource Based IoT Proxy for Bridging Heterogeneous Web Services in IoT Networks.

Science.gov (United States)

Jin, Wenquan; Kim, DoHyeun

2018-05-26

The Internet of Things is comprised of heterogeneous devices, applications, and platforms using multiple communication technologies to connect the Internet for providing seamless services ubiquitously. With the requirement of developing Internet of Things products, many protocols, program libraries, frameworks, and standard specifications have been proposed. Therefore, providing a consistent interface to access services from those environments is difficult. Moreover, bridging the existing web services to sensor and actuator networks is also important for providing Internet of Things services in various industry domains. In this paper, an Internet of Things proxy is proposed that is based on virtual resources to bridge heterogeneous web services from the Internet to the Internet of Things network. The proxy enables clients to have transparent access to Internet of Things devices and web services in the network. The proxy is comprised of server and client to forward messages for different communication environments using the virtual resources which include the server for the message sender and the client for the message receiver. We design the proxy for the Open Connectivity Foundation network where the virtual resources are discovered by the clients as Open Connectivity Foundation resources. The virtual resources represent the resources which expose services in the Internet by web service providers. Although the services are provided by web service providers from the Internet, the client can access services using the consistent communication protocol in the Open Connectivity Foundation network. For discovering the resources to access services, the client also uses the consistent discovery interface to discover the Open Connectivity Foundation devices and virtual resources.

Construction of a nuclear data server using TCP/IP

Energy Technology Data Exchange (ETDEWEB)

Kawano, Toshihiko; Sakai, Osamu [Kyushu Univ., Fukuoka (Japan)

1997-03-01

We construct a nuclear data server which provides data in the evaluated nuclear data library through the network by means of TCP/IP. The client is not necessarily a user but a computer program. Two examples with a prototype server program are demonstrated, the first is data transfer from the server to a user, and the second is to a computer program. (author)

Evaluation of radiological workstations and web-browser-based image distribution clients for a PACS project in hands-on workshops

International Nuclear Information System (INIS)

Boehm, Thomas; Handgraetinger, Oliver; Voellmy, Daniel R.; Marincek, Borut; Wildermuth, Simon; Link, Juergen; Ploner, Ricardo

2004-01-01

The methodology and outcome of a hands-on workshop for the evaluation of PACS (picture archiving and communication system) software for a multihospital PACS project are described. The following radiological workstations and web-browser-based image distribution software clients were evaluated as part of a multistep evaluation of PACS vendors in March 2001: Impax DS 3000 V 4.1/Impax Web1000 (Agfa-Gevaert, Mortsel, Belgium); PathSpeed V 8.0/PathSpeed Web (GE Medical Systems, Milwaukee, Wis., USA); ID Report/ID Web (Image Devices, Idstein, Germany); EasyVision DX/EasyWeb (Philips Medical Systems, Eindhoven, Netherlands); and MagicView 1000 VB33a/MagicWeb (Siemens Medical Systems, Erlangen, Germany). A set of anonymized DICOM test data was provided to enable direct image comparison. Radiologists (n=44) evaluated the radiological workstations and nonradiologists (n=53) evaluated the image distribution software clients using different questionnaires. One vendor was not able to import the provided DICOM data set. Another vendor had problems in displaying imported cross-sectional studies in the correct stack order. Three vendors (Agfa-Gevaert, GE, Philips) presented server-client solutions with web access. Two (Siemens, Image Devices) presented stand-alone solutions. The highest scores in the class of radiological workstations were achieved by ID Report from Image Devices (p<0.005). In the class of image distribution clients, the differences were statistically not significant. Questionnaire-based evaluation was shown to be useful for guaranteeing systematic assessment. The workshop was a great success in raising interest in the PACS project in a large group of future clinical users. The methodology used in the present study may be useful for other hospitals evaluating PACS. (orig.)

PERANCANGAN MAIL SERVER ZIMBRA MENGGUNAKAN TEKNOLOGI VIRTUALISASI STUDI KASUS : SMK PANCAKARYA KOTA TANGERANG

Directory of Open Access Journals (Sweden)

Heru Prasetiawan

2017-05-01

Full Text Available The development of information technology is growing rapidly spur the emergence of new technologies are constantly evolving. The development of technologies that generate more reliable, efficient, economical, and powerful than previous technology. Electronic mail (email is a form of communication and correspondence electronically through a computer system and transmitted to another computer that is intended to traverse the computer network. The existence of mail server is needed to support the communication needs via email. Zimbra Mail Server is implemented using virtualization technology with the operating system Proxmox which is a Linux distribution based on Debian and to guestnya operating system SLES (Suse Linux Enterprise Server. This research was conducted at the agency already has a previous computer networking facilities, so that the research was conducted to complement the needs of the mail server at the institution. The result achieved is a mail application server using virtualization technology that has the facilities and the web-based mail client applications, antivirus and antispam.

Essential Mac OS X panther server administration integrating Mac OS X server into heterogeneous networks

CERN Document Server

Bartosh, Michael

2004-01-01

If you've ever wondered how to safely manipulate Mac OS X Panther Server's many underlying configuration files or needed to explain AFP permission mapping--this book's for you. From the command line to Apple's graphical tools, the book provides insight into this powerful server software. Topics covered include installation, deployment, server management, web application services, data gathering, and more

Request queues for interactive clients in a shared file system of a parallel computing system

Science.gov (United States)

Bent, John M.; Faibish, Sorin

2015-08-18

Interactive requests are processed from users of log-in nodes. A metadata server node is provided for use in a file system shared by one or more interactive nodes and one or more batch nodes. The interactive nodes comprise interactive clients to execute interactive tasks and the batch nodes execute batch jobs for one or more batch clients. The metadata server node comprises a virtual machine monitor; an interactive client proxy to store metadata requests from the interactive clients in an interactive client queue; a batch client proxy to store metadata requests from the batch clients in a batch client queue; and a metadata server to store the metadata requests from the interactive client queue and the batch client queue in a metadata queue based on an allocation of resources by the virtual machine monitor. The metadata requests can be prioritized, for example, based on one or more of a predefined policy and predefined rules.

Multi-client quantum key distribution using wavelength division multiplexing

International Nuclear Information System (INIS)

Grice, Warren P.; Bennink, Ryan S.; Earl, Dennis Duncan; Evans, Philip G.; Humble, Travis S.; Pooser, Raphael C.; Schaake, Jason; Williams, Brian P.

2011-01-01

Quantum Key Distribution (QKD) exploits the rules of quantum mechanics to generate and securely distribute a random sequence of bits to two spatially separated clients. Typically a QKD system can support only a single pair of clients at a time, and so a separate quantum link is required for every pair of users. We overcome this limitation with the design and characterization of a multi-client entangled-photon QKD system with the capacity for up to 100 clients simultaneously. The time-bin entangled QKD system includes a broadband down-conversion source with two unique features that enable the multi-user capability. First, the photons are emitted across a very large portion of the telecom spectrum. Second, and more importantly, the photons are strongly correlated in their energy degree of freedom. Using standard wavelength division multiplexing (WDM) hardware, the photons can be routed to different parties on a quantum communication network, while the strong spectral correlations ensure that each client is linked only to the client receiving the conjugate wavelength. In this way, a single down-conversion source can support dozens of channels simultaneously--and to the extent that the WDM hardware can send different spectral channels to different clients, the system can support multiple client pairings. We will describe the design and characterization of the down-conversion source, as well as the client stations, which must be tunable across the emission spectrum.

Adaptive proxy map server for efficient vector spatial data rendering

Science.gov (United States)

Sayar, Ahmet

2013-01-01

The rapid transmission of vector map data over the Internet is becoming a bottleneck of spatial data delivery and visualization in web-based environment because of increasing data amount and limited network bandwidth. In order to improve both the transmission and rendering performances of vector spatial data over the Internet, we propose a proxy map server enabling parallel vector data fetching as well as caching to improve the performance of web-based map servers in a dynamic environment. Proxy map server is placed seamlessly anywhere between the client and the final services, intercepting users' requests. It employs an efficient parallelization technique based on spatial proximity and data density in case distributed replica exists for the same spatial data. The effectiveness of the proposed technique is proved at the end of the article by the application of creating map images enriched with earthquake seismic data records.

Conflict free network coding for distributed storage networks

KAUST Repository

Al-Habob, Ahmed A.

2015-06-01

© 2015 IEEE. In this paper, we design a conflict free instantly decodable network coding (IDNC) solution for file download from distributed storage servers. Considering previously downloaded files at the clients from these servers as side information, IDNC can speed up the current download process. However, transmission conflicts can occur since multiple servers can simultaneously send IDNC combinations of files to the same client, which can tune to only one of them at a time. To avoid such conflicts and design more efficient coded download patterns, we propose a dual conflict IDNC graph model, which extends the conventional IDNC graph model in order to guarantee conflict free server transmissions to each of the clients. We then formulate the download time minimization problem as a stochastic shortest path problem whose action space is defined by the independent sets of this new graph. Given the intractability of the solution, we design a channel-aware heuristic algorithm and show that it achieves a considerable reduction in the file download time, compared to applying the conventional IDNC approach separately at each of the servers.

CTserver: A Computational Thermodynamics Server for the Geoscience Community

Science.gov (United States)

Kress, V. C.; Ghiorso, M. S.

2006-12-01

The CTserver platform is an Internet-based computational resource that provides on-demand services in Computational Thermodynamics (CT) to a diverse geoscience user base. This NSF-supported resource can be accessed at ctserver.ofm-research.org. The CTserver infrastructure leverages a high-quality and rigorously tested software library of routines for computing equilibrium phase assemblages and for evaluating internally consistent thermodynamic properties of materials, e.g. mineral solid solutions and a variety of geological fluids, including magmas. Thermodynamic models are currently available for 167 phases. Recent additions include Duan, Møller and Weare's model for supercritical C-O-H-S, extended to include SO2 and S2 species, and an entirely new associated solution model for O-S-Fe-Ni sulfide liquids. This software library is accessed via the CORBA Internet protocol for client-server communication. CORBA provides a standardized, object-oriented, language and platform independent, fast, low-bandwidth interface to phase property modules running on the server cluster. Network transport, language translation and resource allocation are handled by the CORBA interface. Users access server functionality in two principal ways. Clients written as browser- based Java applets may be downloaded which provide specific functionality such as retrieval of thermodynamic properties of phases, computation of phase equilibria for systems of specified composition, or modeling the evolution of these systems along some particular reaction path. This level of user interaction requires minimal programming effort and is ideal for classroom use. A more universal and flexible mode of CTserver access involves making remote procedure calls from user programs directly to the server public interface. The CTserver infrastructure relieves the user of the burden of implementing and testing the often complex thermodynamic models of real liquids and solids. A pilot application of this distributed

Analisis Algoritma Pergantian Cache Pada Proxy Web Server Internet Dengan Simulasi

OpenAIRE

Nurwarsito, Heru

2007-01-01

Pertumbuhan jumlah client internet dari waktu ke waktu terus bertambah, maka respon akses internet menjadi semakin lambat. Untuk membantu kecepatan akses tersebut maka diperlukan cache pada Proxy Server. Penelitian ini bertujuan untuk menganalisis performansi Proxy Server pada Jaringan Internet terhadap penggunaan algoritma pergantian cache-nya.Analisis Algoritma Pergantian Cache Pada Proxy Server didesain dengan metoda pemodelan simulasi jaringan internet yang terdiri dari Web server, Proxy ...

Design and Irnplernentation of Distributed Relational DBMS

OpenAIRE

都司, 達夫; 丸山, 正理; 大木下, 俊也; 冨士, 竹仁; 田中, 仁士; 上坂, 利文; 加藤, 昌央; 木本, 茂; 林, 利治; 渡辺, 勝正; TSUJI, Tatsuo; MARUYAMA, Masari; OGINOSIDTA, Toshiya; FUJI, Takehito; TANAKA, Hitoshi

1992-01-01

This paper describes a distributed relational database management system with emphasis on design and implementation. We have designed and constructed the system on the UNIX local area network in our university. It is based upon the SQL standard, and distributed processings are implemented using RPC (Remote Procedure Calls). The main features of出esystem include: (1) Multi -client and multi -server system, (2) Client-based distribution management, (3) Deadlock free concurrency control scheme, (...

Enhancing Scalability in On-Demand Video Streaming Services for P2P Systems

Directory of Open Access Journals (Sweden)

R. Arockia Xavier Annie

2012-01-01

Full Text Available Recently, many video applications like video telephony, video conferencing, Video-on-Demand (VoD, and so forth have produced heterogeneous consumers in the Internet. In such a scenario, media servers play vital role when a large number of concurrent requests are sent by heterogeneous users. Moreover, the server and distributed client systems participating in the Internet communication have to provide suitable resources to heterogeneous users to meet their requirements satisfactorily. The challenges in providing suitable resources are to analyze the user service pattern, bandwidth and buffer availability, nature of applications used, and Quality of Service (QoS requirements for the heterogeneous users. Therefore, it is necessary to provide suitable techniques to handle these challenges. In this paper, we propose a framework for peer-to-peer- (P2P- based VoD service in order to provide effective video streaming. It consists of four functional modules, namely, Quality Preserving Multivariate Video Model (QPMVM for efficient server management, tracker for efficient peer management, heuristic-based content distribution, and light weight incentivized sharing mechanism. The first two of these modules are confined to a single entity of the framework while the other two are distributed across entities. Experimental results show that the proposed framework avoids overloading the server, increases the number of clients served, and does not compromise on QoS, irrespective of the fact that the expected framework is slightly reduced.

Distributed control system for demand response by servers

Science.gov (United States)

Hall, Joseph Edward

Within the broad topical designation of smart grid, research in demand response, or demand-side management, focuses on investigating possibilities for electrically powered devices to adapt their power consumption patterns to better match generation and more efficiently integrate intermittent renewable energy sources, especially wind. Devices such as battery chargers, heating and cooling systems, and computers can be controlled to change the time, duration, and magnitude of their power consumption while still meeting workload constraints such as deadlines and rate of throughput. This thesis presents a system by which a computer server, or multiple servers in a data center, can estimate the power imbalance on the electrical grid and use that information to dynamically change the power consumption as a service to the grid. Implementation on a testbed demonstrates the system with a hypothetical but realistic usage case scenario of an online video streaming service in which there are workloads with deadlines (high-priority) and workloads without deadlines (low-priority). The testbed is implemented with real servers, estimates the power imbalance from the grid frequency with real-time measurements of the live outlet, and uses a distributed, real-time algorithm to dynamically adjust the power consumption of the servers based on the frequency estimate and the throughput of video transcoder workloads. Analysis of the system explains and justifies multiple design choices, compares the significance of the system in relation to similar publications in the literature, and explores the potential impact of the system.

Distributed system for parallel data processing of ECT signals for electromagnetic flaw detection in materials

International Nuclear Information System (INIS)

Guliashki, Vassil; Marinova, Galia

2002-01-01

The paper proposes a distributed system for parallel data processing of ECT signals for flaw detection in materials. The measured data are stored in files on a host computer, where a JAVA server is located. The host computer is connected through Internet to a set of client computers, distributed geographically. The data are distributed from the host computer by means of the JAVA server to the client computers according their requests. The software necessary for the data processing is installed on each client computer in advance. The organization of the data processing on many computers, working simultaneously in parallel, leads to great time reducing, especially in cases when huge amount of data should be processed in very short time. (Author)

GenExp: an interactive web-based genomic DAS client with client-side data rendering.

Directory of Open Access Journals (Sweden)

Bernat Gel Moreno

Full Text Available BACKGROUND: The Distributed Annotation System (DAS offers a standard protocol for sharing and integrating annotations on biological sequences. There are more than 1000 DAS sources available and the number is steadily increasing. Clients are an essential part of the DAS system and integrate data from several independent sources in order to create a useful representation to the user. While web-based DAS clients exist, most of them do not have direct interaction capabilities such as dragging and zooming with the mouse. RESULTS: Here we present GenExp, a web based and fully interactive visual DAS client. GenExp is a genome oriented DAS client capable of creating informative representations of genomic data zooming out from base level to complete chromosomes. It proposes a novel approach to genomic data rendering and uses the latest HTML5 web technologies to create the data representation inside the client browser. Thanks to client-side rendering most position changes do not need a network request to the server and so responses to zooming and panning are almost immediate. In GenExp it is possible to explore the genome intuitively moving it with the mouse just like geographical map applications. Additionally, in GenExp it is possible to have more than one data viewer at the same time and to save the current state of the application to revisit it later on. CONCLUSIONS: GenExp is a new interactive web-based client for DAS and addresses some of the short-comings of the existing clients. It uses client-side data rendering techniques resulting in easier genome browsing and exploration. GenExp is open source under the GPL license and it is freely available at http://gralggen.lsi.upc.edu/recerca/genexp.

Earth science big data at users' fingertips: the EarthServer Science Gateway Mobile

Science.gov (United States)

Barbera, Roberto; Bruno, Riccardo; Calanducci, Antonio; Fargetta, Marco; Pappalardo, Marco; Rundo, Francesco

2014-05-01

The EarthServer project (www.earthserver.eu), funded by the European Commission under its Seventh Framework Program, aims at establishing open access and ad-hoc analytics on extreme-size Earth Science data, based on and extending leading-edge Array Database technology. The core idea is to use database query languages as client/server interface to achieve barrier-free "mix & match" access to multi-source, any-size, multi-dimensional space-time data -- in short: "Big Earth Data Analytics" - based on the open standards of the Open Geospatial Consortium Web Coverage Processing Service (OGC WCPS) and the W3C XQuery. EarthServer combines both, thereby achieving a tight data/metadata integration. Further, the rasdaman Array Database System (www.rasdaman.com) is extended with further space-time coverage data types. On server side, highly effective optimizations - such as parallel and distributed query processing - ensure scalability to Exabyte volumes. In this contribution we will report on the EarthServer Science Gateway Mobile, an app for both iOS and Android-based devices that allows users to seamlessly access some of the EarthServer applications using SAML-based federated authentication and fine-grained authorisation mechanisms.

Client and event driven data hub system at CDF

International Nuclear Information System (INIS)

Kilminster, Ben; McFarland, Kevin; Vaiciulis, Tony; Matsunaga, Hiroyuki; Shimojima, Makoto

2001-01-01

The Consumer-Server Logger (CSL) system at the Collider Detector at Fermilab is a client and event driven data hub capable of receiving physics events from multiple connections, and logging them to multiple streams while distributing them to multiple online analysis programs (consumers). Its multiple-partitioned design allows data flowing through different paths of the detector sub-systems to be processed separately. The CSL system, using a set of internal memory buffers and message queues mapped to the location of events within its programs, and running on an SGI 2200 Server, is able to process at least the required 20 MB/s of constant event logging (75 Hz of 250 KB events) while also filtering up to 10 MB/s to consumers requesting specific types of events

Application of the distributed genetic algorithm for in-core fuel optimization problems under parallel computational environment

International Nuclear Information System (INIS)

Yamamoto, Akio; Hashimoto, Hiroshi

2002-01-01

The distributed genetic algorithm (DGA) is applied for loading pattern optimization problems of the pressurized water reactors. A basic concept of DGA follows that of the conventional genetic algorithm (GA). However, DGA equally distributes candidates of solutions (i.e. loading patterns) to several independent ''islands'' and evolves them in each island. Communications between islands, i.e. migrations of some candidates between islands are performed with a certain period. Since candidates of solutions independently evolve in each island while accepting different genes of migrants, premature convergence in the conventional GA can be prevented. Because many candidate loading patterns should be evaluated in GA or DGA, the parallelization is efficient to reduce turn around time. Parallel efficiency of DGA was measured using our optimization code and good efficiency was attained even in a heterogeneous cluster environment due to dynamic distribution of the calculation load. The optimization code is based on the client/server architecture with the TCP/IP native socket and a client (optimization) module and calculation server modules communicate the objects of loading patterns each other. Throughout the sensitivity study on optimization parameters of DGA, a suitable set of the parameters for a test problem was identified. Finally, optimization capability of DGA and the conventional GA was compared in the test problem and DGA provided better optimization results than the conventional GA. (author)

WPS-based technology for client-side remote sensing data processing

Directory of Open Access Journals (Sweden)

E. Kazakov

2015-04-01

that the processing servers could play the role of the clients connecting to the service supply server. The study was partially supported by Russian Foundation for Basic Research (RFBR, research project No. 13-05-12079 ofi_m.

Distributed metadata servers for cluster file systems using shared low latency persistent key-value metadata store

Science.gov (United States)

Bent, John M.; Faibish, Sorin; Pedone, Jr., James M.; Tzelnic, Percy; Ting, Dennis P. J.; Ionkov, Latchesar A.; Grider, Gary

2017-12-26

A cluster file system is provided having a plurality of distributed metadata servers with shared access to one or more shared low latency persistent key-value metadata stores. A metadata server comprises an abstract storage interface comprising a software interface module that communicates with at least one shared persistent key-value metadata store providing a key-value interface for persistent storage of key-value metadata. The software interface module provides the key-value metadata to the at least one shared persistent key-value metadata store in a key-value format. The shared persistent key-value metadata store is accessed by a plurality of metadata servers. A metadata request can be processed by a given metadata server independently of other metadata servers in the cluster file system. A distributed metadata storage environment is also disclosed that comprises a plurality of metadata servers having an abstract storage interface to at least one shared persistent key-value metadata store.

Performance Characteristics of Mirror Servers on the Internet

National Research Council Canada - National Science Library

Meyers, Andy

1998-01-01

... retrieved. In this paper we present findings from measuring 9 clients scattered throughout the United States retrieving over 490,000 documents from 45 production web servers which mirror three different sites...

CyberWalk : a web-based distributed virtual walkthrough environment.

OpenAIRE

Chim, J.; Lau, R. W. H.; Leong, H. V.; Si, A.

2003-01-01

A distributed virtual walkthrough environment allows users connected to the geometry server to walk through a specific place of interest, without having to travel physically. This place of interest may be a virtual museum, virtual library or virtual university. There are two basic approaches to distribute the virtual environment from the geometry server to the clients, complete replication and on-demand transmission. Although the on-demand transmission approach saves waiting time and optimize...

A DISTRIBUTED HYPERMAP MODEL FOR INTERNET GIS

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

The rapid development of Internet technology makes it possible to integrate GIS with the Internet,forming Internet GIS.Internet GIS is based on a distributed client/server architecture and TCP/IP & IIOP.When constructing and designing Internet GIS,we face the problem of how to express information units of Internet GIS.In order to solve this problem,this paper presents a distributed hypermap model for Internet GIS.This model provides a solution to organize and manage Internet GIS information units.It also illustrates relations between two information units and in an internal information unit both on clients and servers.On the basis of this model,the paper contributes to the expressions of hypermap relations and hypermap operations.The usage of this model is shown in the implementation of a prototype system.

Energy-efficient server management; Energieeffizientes Servermanagement

Energy Technology Data Exchange (ETDEWEB)

Sauter, B.

2003-07-01

This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that aimed to develop an automatic shut-down system for the servers used in typical electronic data processing installations to be found in small and medium-sized enterprises. The purpose of shutting down these computers - the saving of energy - is discussed. The development of a shutdown unit on the basis of a web-server that automatically shuts down the servers connected to it and then interrupts their power supply is described. The functions of the unit, including pre-set times for switching on and off, remote operation via the Internet and its interaction with clients connected to it are discussed. Examples of the system's user interface are presented.

Microsoft® Exchange Server 2007 Administrator's Companion

CERN Document Server

Glenn, Walter; Maher, Joshua

2009-01-01

Get your mission-critical messaging and collaboration systems up and running with the essential guide to deploying and managing Exchange Server 2007, now updated for SP1. This comprehensive administrator's reference covers the full range of server and client deployments, unified communications, security features, performance optimization, troubleshooting, and disaster recovery. It also includes four chapters on security policy, tools, and techniques to help protect messaging systems from viruses, spam, and phishing. Written by expert authors Walter Glenn and Scott Lowe, this reference deliver

Understanding the usage of the Helioviewer Project clients and services

Science.gov (United States)

Ireland, J.; Zahniy, S.; Mueller, D.; Nicula, B.; Verstringe, F.; Bourgoignie, B.; Buchlin, E.; Alingery, P.

2017-12-01

The Helioviewer Project enables visual exploration of the Sun and the inner heliosphere for everyone, everywhere via intuitive interfaces and novel technology. The project mainly develops two clients, helioviewer.org and JHelioviewer, and the server-side capabilities accessed via those clients. Images from many different ground and space-based sources are currently available from multiple servers. Solar and heliospheric feature and event information, magnetic field extrapolations and important time-series can also be browsed and visualized using Helioviewer Project clients. Users of the Helioviewer Project have made over two million movies and many millions of screenshots since detailed (and anonymous) logging of Helioviewer Project usage was implemented in February 2011. These usage logs are analyzed to give a detailed breakdown on user interaction with solar and heliospheric data via Helioviewer Project clients and services. We present summary statistics on how our users are using our clients and services, which data they are interested in, and how they choose to interact with different data sources. At the poster presentation we will also be soliciting ideas from the community to improve our clients and services.

Worldwide telemedicine services based on distributed multimedia electronic patient records by using the second generation Web server hyperwave.

Science.gov (United States)

Quade, G; Novotny, J; Burde, B; May, F; Beck, L E; Goldschmidt, A

1999-01-01

A distributed multimedia electronic patient record (EPR) is a central component of a medicine-telematics application that supports physicians working in rural areas of South America, and offers medical services to scientists in Antarctica. A Hyperwave server is used to maintain the patient record. As opposed to common web servers--and as a second generation web server--Hyperwave provides the capability of holding documents in a distributed web space without the problem of broken links. This enables physicians to browse through a patient's record by using a standard browser even if the patient's record is distributed over several servers. The patient record is basically implemented on the "Good European Health Record" (GEHR) architecture.

A distributed, graphical user interface based, computer control system for atomic physics experiments.

Science.gov (United States)

Keshet, Aviv; Ketterle, Wolfgang

2013-01-01

Atomic physics experiments often require a complex sequence of precisely timed computer controlled events. This paper describes a distributed graphical user interface-based control system designed with such experiments in mind, which makes use of off-the-shelf output hardware from National Instruments. The software makes use of a client-server separation between a user interface for sequence design and a set of output hardware servers. Output hardware servers are designed to use standard National Instruments output cards, but the client-server nature should allow this to be extended to other output hardware. Output sequences running on multiple servers and output cards can be synchronized using a shared clock. By using a field programmable gate array-generated variable frequency clock, redundant buffers can be dramatically shortened, and a time resolution of 100 ns achieved over effectively arbitrary sequence lengths.

A distributed, graphical user interface based, computer control system for atomic physics experiments

Science.gov (United States)

Keshet, Aviv; Ketterle, Wolfgang

2013-01-01

Atomic physics experiments often require a complex sequence of precisely timed computer controlled events. This paper describes a distributed graphical user interface-based control system designed with such experiments in mind, which makes use of off-the-shelf output hardware from National Instruments. The software makes use of a client-server separation between a user interface for sequence design and a set of output hardware servers. Output hardware servers are designed to use standard National Instruments output cards, but the client-server nature should allow this to be extended to other output hardware. Output sequences running on multiple servers and output cards can be synchronized using a shared clock. By using a field programmable gate array-generated variable frequency clock, redundant buffers can be dramatically shortened, and a time resolution of 100 ns achieved over effectively arbitrary sequence lengths.

Advancing the Power and Utility of Server-Side Aggregation

Science.gov (United States)

Fulker, Dave; Gallagher, James

2016-01-01

During the upcoming Summer 2016 meeting of the ESIP Federation (July 19-22), OpenDAP will hold a Developers and Users Workshop. While a broad set of topics will be covered, a key focus is capitalizing on recent EOSDIS-sponsored advances in Hyrax, OPeNDAPs own software for server-side realization of the DAP2 and DAP4 protocols. These Hyrax advances are as important to data users as to data providers, and the workshop will include hands-on experiences of value to both. Specifically, a balanced set of presentations and hands-on tutorials will address advances in1.server installation,2.server configuration,3.Hyrax aggregation capabilities,4.support for data-access from clients that are HTTP-based, JSON-based or OGC-compliant (especially WCS and WMS),5.support for DAP4,6.use and extension of server-side computational capabilities, and7.several performance-affecting matters.Topics 2 through 7 will be relevant to data consumers, data providers andnotably, due to the open-source nature of all OPeNDAP softwareto developers wishing to extend Hyrax, to build compatible clients and servers, andor to employ Hyrax as middleware that enables interoperability across a variety of end-user and source-data contexts. A session for contributed talks will elaborate the topics listed above and embrace additional ones.

Application of the distributed genetic algorithm for loading pattern optimization problems

International Nuclear Information System (INIS)

Hashimoto, Hiroshi; Yamamoto, Akio

2000-01-01

The distributed genetic algorithm (DGA) is applied for loading pattern optimization problems of the pressurized water reactors (PWR). Due to stiff nature of the loading pattern optimizations (e.g. multi-modality and non-linearity), stochastic methods like the simulated annealing or the genetic algorithm (GA) are widely applied for these problems. A basic concept of DGA is based on that of GA. However, DGA equally distributes candidates of solutions (i.e. loading patterns) to several independent 'islands' and evolves them in each island. Migrations of some candidates are performed among islands with a certain period. Since candidates of solutions independently evolve in each island with accepting different genes of migrants from other islands, premature convergence in the traditional GA can be prevented. Because many candidate loading patterns should be evaluated in one generation of GA or DGA, the parallelization in these calculations works efficiently. Parallel efficiency was measured using our optimization code and good load balance was attained even in a heterogeneous cluster environment due to dynamic distribution of the calculation load. The optimization code is based on the client/server architecture with the TCP/IP native socket and a client (optimization module) and calculation server modules communicate the objects of loading patterns each other. Throughout the sensitivity study on optimization parameters of DGA, a suitable set of the parameters for a test problem was identified. Finally, optimization capability of DGA and the traditional GA was compared in the test problem and DGA provided better optimization results than the traditional GA. (author)

The Performance and Compatibility of Thin Client Computing with Fleet Operations

National Research Council Canada - National Science Library

Landry, Kenneth J

2006-01-01

...) with a thin client/server-based computing (TCSBC) architecture. After becoming nearly extinct in the early 1990s, thin clients are emerging on the forefront of technology with numerous bandwidth improvements and cost reduction benefits...

A client-server software for the identification of groundwater vulnerability to pesticides at regional level.

Science.gov (United States)

Di Guardo, Andrea; Finizio, Antonio

2015-10-15

The groundwater VULnerability to PESticide software system (VULPES) is a user-friendly, GIS-based and client-server software developed to identify vulnerable areas to pesticides at regional level making use of pesticide fate models. It is a Decision Support System aimed to assist the public policy makers to investigate areas sensitive to specific substances and to propose limitations of use or mitigation measures. VULPES identify the so-called Uniform Geographical Unit (UGU) which are areas characterised by the same agro-environmental conditions. In each UGU it applies the PELMO model obtaining the 80th percentile of the substance concentration at 1 metre depth; then VULPES creates a vulnerability map in shapefile format which classifies the outputs comparing them with the lower threshold set to the legal limit concentration in groundwater (0.1 μg/l). This paper describes the software structure in details and a case study with the application of the terbuthylazine herbicide on the Lombardy region territory. Three zones with different degrees of vulnerabilities has been identified and described. Copyright © 2015 Elsevier B.V. All rights reserved.

A Distributed Approach to Continuous Monitoring of Constrained k-Nearest Neighbor Queries in Road Networks

Directory of Open Access Journals (Sweden)

Hyung-Ju Cho

2012-01-01

Full Text Available Given two positive parameters k and r, a constrained k-nearest neighbor (CkNN query returns the k closest objects within a network distance r of the query location in road networks. In terms of the scalability of monitoring these CkNN queries, existing solutions based on central processing at a server suffer from a sudden and sharp rise in server load as well as messaging cost as the number of queries increases. In this paper, we propose a distributed and scalable scheme called DAEMON for the continuous monitoring of CkNN queries in road networks. Our query processing is distributed among clients (query objects and server. Specifically, the server evaluates CkNN queries issued at intersections of road segments, retrieves the objects on the road segments between neighboring intersections, and sends responses to the query objects. Finally, each client makes its own query result using this server response. As a result, our distributed scheme achieves close-to-optimal communication costs and scales well to large numbers of monitoring queries. Exhaustive experimental results demonstrate that our scheme substantially outperforms its competitor in terms of query processing time and messaging cost.

System of and method for transparent management of data objects in containers across distributed heterogenous resources

Science.gov (United States)

Moore, Reagan W.; Rajasekar, Arcot; Wan, Michael Y.

2007-09-11

A system of and method for maintaining data objects in containers across a network of distributed heterogeneous resources in a manner which is transparent to a client. A client request pertaining to containers is resolved by querying meta data for the container, processing the request through one or more copies of the container maintained on the system, updating the meta data for the container to reflect any changes made to the container as a result processing the re quest, and, if a copy of the container has changed, changing the status of the copy to indicate dirty status or synchronizing the copy to one or more other copies that may be present on the system.

Distributed software framework and continuous integration in hydroinformatics systems

Science.gov (United States)

Zhou, Jianzhong; Zhang, Wei; Xie, Mengfei; Lu, Chengwei; Chen, Xiao

2017-08-01

When encountering multiple and complicated models, multisource structured and unstructured data, complex requirements analysis, the platform design and integration of hydroinformatics systems become a challenge. To properly solve these problems, we describe a distributed software framework and it’s continuous integration process in hydroinformatics systems. This distributed framework mainly consists of server cluster for models, distributed database, GIS (Geographic Information System) servers, master node and clients. Based on it, a GIS - based decision support system for joint regulating of water quantity and water quality of group lakes in Wuhan China is established.

Surfing for Data: A Gathering Trend in Data Storage Is the Use of Web-Based Applications that Make It Easy for Authorized Users to Access Hosted Server Content with Just a Computing Device and Browser

Science.gov (United States)

Technology & Learning, 2005

2005-01-01

In recent years, the widespread availability of networks and the flexibility of Web browsers have shifted the industry from a client-server model to a Web-based one. In the client-server model of computing, clients run applications locally, with the servers managing storage, printing functions, and network traffic. Because every client is…

Distributed MDSplus database performance with Linux clusters

International Nuclear Information System (INIS)

Minor, D.H.; Burruss, J.R.

2006-01-01

The staff at the DIII-D National Fusion Facility, operated for the USDOE by General Atomics, are investigating the use of grid computing and Linux technology to improve performance in our core data management services. We are in the process of converting much of our functionality to cluster-based and grid-enabled software. One of the most important pieces is a new distributed version of the MDSplus scientific data management system that is presently used to support fusion research in over 30 countries worldwide. To improve data handling performance, the staff is investigating the use of Linux clusters for both data clients and servers. The new distributed capability will result in better load balancing between these clients and servers, and more efficient use of network resources resulting in improved support of the data analysis needs of the scientific staff

Distributed usability evaluation

DEFF Research Database (Denmark)

Christensen, Lars; Frøkjær, Erik

2010-01-01

We present DUE (Distributed Usability Evaluation), a technique for collecting and evaluating usability data. The DUE infrastructure involves a client-server network. A client-based tool resides on the workstation of each user, providing a screen video recording, microphone input of voice commentary......, and a window for a severity rating. The idea is for the user to work naturalistically, clicking a button when a usability problem or point of uncertainty is encountered, to describe it verbally along with illustrating it on screen, and to rate its severity. These incidents are accumulated on a server......, providing access to an evaluator (usability expert) and to product developers or managers who want to review the incidents and analyse them. DUE supports evaluation in the development stages from running prototypes and onwards. A case study of the use of DUE in a corporate environment is presented...

PONDEROSA-C/S: client–server based software package for automated protein 3D structure determination

OpenAIRE

Lee, Woonghee; Stark, Jaime L.; Markley, John L.

2014-01-01

Peak-picking Of Noe Data Enabled by Restriction Of Shift Assignments-Client Server (PONDEROSA-C/S) builds on the original PONDEROSA software (Lee et al. in Bioinformatics 27:1727–1728. doi:10.1093/bioinformatics/btr200, 2011) and includes improved features for structure calculation and refinement. PONDEROSA-C/S consists of three programs: Ponderosa Server, Ponderosa Client, and Ponderosa Analyzer. PONDEROSA-C/S takes as input the protein sequence, a list of assigned chemical shifts, and nucle...

Interactive client side data visualization with d3.js

Science.gov (United States)

Rodzianko, A.; Versteeg, R.; Johnson, D. V.; Soltanian, M. R.; Versteeg, O. J.; Girouard, M.

2015-12-01

Geoscience data associated with near surface research and operational sites is increasingly voluminous and heterogeneous (both in terms of providers and data types - e.g. geochemical, hydrological, geophysical, modeling data, of varying spatiotemporal characteristics). Such data allows scientists to investigate fundamental hydrological and geochemical processes relevant to agriculture, water resources and climate change. For scientists to easily share, model and interpret such data requires novel tools with capabilities for interactive data visualization. Under sponsorship of the US Department of Energy, Subsurface Insights is developing the Predictive Assimilative Framework (PAF): a cloud based subsurface monitoring platform which can manage, process and visualize large heterogeneous datasets. Over the last year we transitioned our visualization method from a server side approach (in which images and animations were generated using Jfreechart and Visit) to a client side one that utilizes the D3 Javascript library. Datasets are retrieved using web service calls to the server, returned as JSON objects and visualized within the browser. Users can interactively explore primary and secondary datasets from various field locations. Our current capabilities include interactive data contouring and heterogeneous time series data visualization. While this approach is very powerful and not necessarily unique, special attention needs to be paid to latency and responsiveness issues as well as to issues as cross browser code compatibility so that users have an identical, fluid and frustration-free experience across different computational platforms. We gratefully acknowledge support from the US Department of Energy under SBIR Award DOE DE-SC0009732, the use of data from the Lawrence Berkeley National Laboratory (LBNL) Sustainable Systems SFA Rifle field site and collaboration with LBNL SFA scientists.

PENGUKURAN KINERJA ROUND-ROBIN SCHEDULER UNTUK LINUX VIRTUAL SERVER PADA KASUS WEB SERVER

Directory of Open Access Journals (Sweden)

Royyana Muslim Ijtihadie

2005-07-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Dengan meningkatnya perkembangan jumlah pengguna internet dan mulai diadopsinya penggunaan internet dalam kehidupan sehari-hari, maka lalulintas data di Internet telah meningkat secara signifikan. Sejalan dengan itu pula beban kerja server-server yang memberikan service di Internet juga mengalami kenaikan yang cukup signifikan. Hal tersebut dapat mengakibatkan suatu server mengalami kelebihan beban pada suatu saat. Untuk mengatasi hal tersebut maka diterapkan skema konfigurasi server cluster menggunakan konsep load balancing. Load balancing server menerapkan algoritma dalam melakukan pembagian tugas. Algoritma round robin telah digunakan pada Linux Virtual Server. Penelitian ini melakukan pengukuran kinerja terhadap Linux Virtual Server yang menggunakan algoritma round robin untuk melakukan penjadwalan pembagian beban terhadap server. Penelitian ini mengukur performa dari sisi client yang mencoba mengakses web server.performa yang diukur adalah jumlah request yang bisa diselesaikan perdetik (request per second, waktu untuk menyelesaikan per satu request, dan   throughput yang dihasilkan. Dari hasil percobaan didapatkan bahwa penggunaan LVS bisa meningkatkan performa, yaitu menaikkan jumlah request per detik

Characteristics and Energy Use of Volume Servers in the United States

Energy Technology Data Exchange (ETDEWEB)

Fuchs, H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shehabi, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ganeshalingam, M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Desroches, L. -B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lim, B. [Fraunhofer Center for Sustainable Energy Systems, Boston, MA (United States); Roth, K. [Fraunhofer Center for Sustainable Energy Systems, Boston, MA (United States); Tsao, A. [Navigant Consulting Inc., Chicago, IL (United States)

2017-11-01

Servers’ field energy use remains poorly understood, given heterogeneous computing loads, configurable hardware and software, and operation over a wide range of management practices. This paper explores various characteristics of 1- and 2-socket volume servers that affect energy consumption, and quantifies the difference in power demand between higher-performing SPEC and ENERGY STAR servers and our best understanding of a typical server operating today. We first establish general characteristics of the U.S. installed base of volume servers from existing IDC data and the literature, before presenting information on server hardware configurations from data collection events at a major online retail website. We then compare cumulative distribution functions of server idle power across three separate datasets and explain the differences between them via examination of the hardware characteristics to which power draw is most sensitive. We find that idle server power demand is significantly higher than ENERGY STAR benchmarks and the industry-released energy use documented in SPEC, and that SPEC server configurations—and likely the associated power-scaling trends—are atypical of volume servers. Next, we examine recent trends in server power draw among high-performing servers across their full load range to consider how representative these trends are of all volume servers before inputting weighted average idle power load values into a recently published model of national server energy use. Finally, we present results from two surveys of IT managers (n=216) and IT vendors (n=178) that illustrate the prevalence of more-efficient equipment and operational practices in server rooms and closets; these findings highlight opportunities to improve the energy efficiency of the U.S. server stock.

Developing Server-Side Infrastructure for Large-Scale E-Learning of Web Technology

Science.gov (United States)

Simpkins, Neil

2010-01-01

The growth of E-business has made experience in server-side technology an increasingly important area for educators. Server-side skills are in increasing demand and recognised to be of relatively greater value than comparable client-side aspects (Ehie, 2002). In response to this, many educational organisations have developed E-business courses,…

JobCenter: an open source, cross-platform, and distributed job queue management system optimized for scalability and versatility.

Science.gov (United States)

Jaschob, Daniel; Riffle, Michael

2012-07-30

Laboratories engaged in computational biology or bioinformatics frequently need to run lengthy, multistep, and user-driven computational jobs. Each job can tie up a computer for a few minutes to several days, and many laboratories lack the expertise or resources to build and maintain a dedicated computer cluster. JobCenter is a client-server application and framework for job management and distributed job execution. The client and server components are both written in Java and are cross-platform and relatively easy to install. All communication with the server is client-driven, which allows worker nodes to run anywhere (even behind external firewalls or "in the cloud") and provides inherent load balancing. Adding a worker node to the worker pool is as simple as dropping the JobCenter client files onto any computer and performing basic configuration, which provides tremendous ease-of-use, flexibility, and limitless horizontal scalability. Each worker installation may be independently configured, including the types of jobs it is able to run. Executed jobs may be written in any language and may include multistep workflows. JobCenter is a versatile and scalable distributed job management system that allows laboratories to very efficiently distribute all computational work among available resources. JobCenter is freely available at http://code.google.com/p/jobcenter/.

Improvements to the National Transport Code Collaboration Data Server

Science.gov (United States)

Alexander, David A.

2001-10-01

The data server of the National Transport Code Colaboration Project provides a universal network interface to interpolated or raw transport data accessible by a universal set of names. Data can be acquired from a local copy of the Iternational Multi-Tokamak (ITER) profile database as well as from TRANSP trees of MDS Plus data systems on the net. Data is provided to the user's network client via a CORBA interface, thus providing stateful data server instances, which have the advantage of remembering the desired interpolation, data set, etc. This paper will review the status and discuss the recent improvements made to the data server, such as the modularization of the data server and the addition of hdf5 and MDS Plus data file writing capability.

Development of Client-Server Application by Using UDP Socket Programming for Remotely Monitoring CNC Machine Environment in Fixture Process

Directory of Open Access Journals (Sweden)

Darmawan Darmawan

2016-08-01

Full Text Available The use of computer technology in manufacturing industries can improve manufacturing flexibility significantly, especially in manufacturing processes; many software applications have been utilized to improve machining performance. However, none of them has discussed the abilities to perform direct machining. In this paper, an integrated system for remote operation and monitoring of Computer Numerical Control (CNC machines is put into consideration. The integrated system includes computerization, network technology, and improved holding mechanism. The work proposed by this research is mainly on the software development for such integrated system. It uses Java three-dimensional (3D programming and Virtual Reality Modeling Language (VRML at the client side for visualization of machining environment. This research is aimed at developing a control system to remotely operate and monitor a self-reconfiguration fixture mechanism of a CNC milling machine through internet connection and integration of Personal Computer (PC-based CNC controller, a server side, a client side and CNC milling. The performance of the developed system was evaluated by testing with one type of common protocols particularly User Datagram Protocol (UDP.  Using UDP, the developed system requires 3.9 seconds to complete the close clamping, less than 1 second to release the clamping and it can deliver 463 KiloByte.

CORAL Server and CORAL Server Proxy: Scalable Access to Relational Databases from CORAL Applications

International Nuclear Information System (INIS)

Valassi, A; Kalkhof, A; Bartoldus, R; Salnikov, A; Wache, M

2011-01-01

The CORAL software is widely used at CERN by the LHC experiments to access the data they store on relational databases, such as Oracle. Two new components have recently been added to implement a model involving a middle tier 'CORAL server' deployed close to the database and a tree of 'CORAL server proxies', providing data caching and multiplexing, deployed close to the client. A first implementation of the two new components, released in the summer 2009, is now deployed in the ATLAS online system to read the data needed by the High Level Trigger, allowing the configuration of a farm of several thousand processes. This paper reviews the architecture of the software, its development status and its usage in ATLAS.

Distributed password cracking

OpenAIRE

Crumpacker, John R.

2009-01-01

Approved for public release, distribution unlimited Password cracking requires significant processing power, which in today's world is located at a workstation or home in the form of a desktop computer. Berkeley Open Infrastructure for Network Computing (BOINC) is the conduit to this significant source of processing power and John the Ripper is the key. BOINC is a distributed data processing system that incorporates client-server relationships to generically process data. The BOINC structu...

Development in distributed beam-view

International Nuclear Information System (INIS)

Bhole, R.B.; Pal, Satbajit; Dasgupta, S.

2003-01-01

A computerized distributed beam-viewer has been developed using PC-add on image digitizer card plugged into a Pentium PC running Windows NT. Image Acquisition card (IMAQ-1408) from National Instruments is driven to digitise inputs from CCD cameras placed along the beam transport lines. The multiple clients situated across a switched Ethernet LAN, collects the data and displays beam-views on a desirable Window size. Only one privilege client at the control room has the selection facility of the channel (camera), whereas image display processing and storing facility are provided at all other clients end. The client server S/W written on Window SDK is implemented using Window Socket ver 2.0 library functions. (author)

MEMBANGUN SERVER BERBASIS LINUX PADA JARINGAN LAN DI LABOR SISTEM INFORMASI JURUSAN TEKNOLOGI INFORMASI POLITEKNIK NEGERI PADANG

Directory of Open Access Journals (Sweden)

Fifi Rasyidah

2014-03-01

Full Text Available The System Information Laboratory of Information Technology Department Polytechnic State of Padang has 30 units computer as education facilities to support learning process. All of computers used at same time in a learning section. This case causing trouble to monitoring each students activities. In order to get the solution for the lecturer, the writer then construct a server by using Linux operation system and client by using windows system operation in which Samba File Server is needed. By using this samba, the lecturer will be able to share the data and will be able to use the server as data storage media. Besides that, the writer will also use VNC (Virtual network connection to simplify the process of monitoring and supervising client working system. Based on the result gotten after the writer done some experiment, it can be concluded that Samba File Server can also be used after some configuration is applied on certain files. Moreover, the writer also conclude that VNC can control the entire of the client. The writer suggests that Samba File server which will be used is the latest version one which has more feature than the previous one, it is suggested that the configuration of VNC is applied on Ubuntu Linux since the service is available. Kata Kunci : Samba File Server, VNC, Ubuntu installation

SPEER-SERVER: a web server for prediction of protein specificity determining sites.

Science.gov (United States)

Chakraborty, Abhijit; Mandloi, Sapan; Lanczycki, Christopher J; Panchenko, Anna R; Chakrabarti, Saikat

2012-07-01

Sites that show specific conservation patterns within subsets of proteins in a protein family are likely to be involved in the development of functional specificity. These sites, generally termed specificity determining sites (SDS), might play a crucial role in binding to a specific substrate or proteins. Identification of SDS through experimental techniques is a slow, difficult and tedious job. Hence, it is very important to develop efficient computational methods that can more expediently identify SDS. Herein, we present Specificity prediction using amino acids' Properties, Entropy and Evolution Rate (SPEER)-SERVER, a web server that predicts SDS by analyzing quantitative measures of the conservation patterns of protein sites based on their physico-chemical properties and the heterogeneity of evolutionary changes between and within the protein subfamilies. This web server provides an improved representation of results, adds useful input and output options and integrates a wide range of analysis and data visualization tools when compared with the original standalone version of the SPEER algorithm. Extensive benchmarking finds that SPEER-SERVER exhibits sensitivity and precision performance that, on average, meets or exceeds that of other currently available methods. SPEER-SERVER is available at http://www.hpppi.iicb.res.in/ss/.

Linux Server Hacks, 2 Tips & Tools for Connecting, Monitoring, and Troubleshooting

CERN Document Server

von Hagen, William

2009-01-01

This handy reference offers 100 completely new server management tips and techniques designed to improve your productivity and sharpen your administrative skills. Each hack represents a clever way to accomplish a specific task, saving you countless hours of searching for the right answer. And you don't have to be a system administrator with hundreds of boxen to get something useful from this book as many of the hacks apply equally well to a single system or a home network. Whether they help you recover lost data, collect information from distributed clients, or synchronize administrative envir

On Non-Parallelizable Deterministic Client Puzzle Scheme with Batch Verification Modes

NARCIS (Netherlands)

Tang, Qiang; Jeckmans, Arjan

A (computational) client puzzle scheme enables a client to prove to a server that a certain amount of computing resources (CPU cycles and/or Memory look-ups) has been dedicated to solve a puzzle. Researchers have identified a number of potential applications, such as constructing timed cryptography,

An experimental study of client-side Spotify peering behaviour

OpenAIRE

Ellis, M.; Strowes, S.; Perkins, C.

2011-01-01

Spotify is a popular music-streaming service which has seen widespread use across Europe. While Spotify’s server-side behaviour has previously been studied, little is known about the client-side behaviour. In this paper, we describe an experimental study where we collect packet headers for Spotify traffic over multiple 24-hour time frames at a client host. Two distinct types of behaviour are observed, when tracks are being downloaded, and when the client is only serving requests from other pe...

User-Level QoS-Adaptive Resource Management in Server End-Systems

National Research Council Canada - National Science Library

Abdelzaher, Tarek F; Shin, Kang G; Bhatti, Nina

2003-01-01

Proliferation of QoS-sensitive client-server Internet applications such as high-quality audio, video-on-demand, e-commerce, and commercial web hosting has generated an impetus to provide performance guarantees...

Reusable Client-Side JavaScript Modules for Immersive Web-Based Real-Time Collaborative Neuroimage Visualization.

Science.gov (United States)

Bernal-Rusiel, Jorge L; Rannou, Nicolas; Gollub, Randy L; Pieper, Steve; Murphy, Shawn; Robertson, Richard; Grant, Patricia E; Pienaar, Rudolph

2017-01-01

In this paper we present a web-based software solution to the problem of implementing real-time collaborative neuroimage visualization. In both clinical and research settings, simple and powerful access to imaging technologies across multiple devices is becoming increasingly useful. Prior technical solutions have used a server-side rendering and push-to-client model wherein only the server has the full image dataset. We propose a rich client solution in which each client has all the data and uses the Google Drive Realtime API for state synchronization. We have developed a small set of reusable client-side object-oriented JavaScript modules that make use of the XTK toolkit, a popular open-source JavaScript library also developed by our team, for the in-browser rendering and visualization of brain image volumes. Efficient realtime communication among the remote instances is achieved by using just a small JSON object, comprising a representation of the XTK image renderers' state, as the Google Drive Realtime collaborative data model. The developed open-source JavaScript modules have already been instantiated in a web-app called MedView , a distributed collaborative neuroimage visualization application that is delivered to the users over the web without requiring the installation of any extra software or browser plugin. This responsive application allows multiple physically distant physicians or researchers to cooperate in real time to reach a diagnosis or scientific conclusion. It also serves as a proof of concept for the capabilities of the presented technological solution.

PENGEMBANGAN PENCEGAHAN SERANGAN DISTRIBUTED DENIAL OF SERVICE (DDOS PADA SUMBER DAYA JARINGAN DENGAN INTEGRASI NETWORK BEHAVIOR ANALYSIS DAN CLIENT PUZZLE

Directory of Open Access Journals (Sweden)

Septian Geges

2015-01-01

Full Text Available Denial of Service (DoS merupakan permasalahan keamanan jaringan yang sampai saat ini terus berkembang secara dinamis. Semakin tinggi kemampuan komputasi suatu komputer penyerang, serangan DoS yang dapat dihasilkan juga semakin membahayakan. Serangan ini dapat mengakibatkan ketidakmampuan server untuk melayani service request yang sah. Karena itu serangan DoS sangat merugikan dan perlu diberikan pencegahan yang efektif. Ancaman berikutnya yang juga sangat membahayakan adalah Distributed Denial of Service (DDoS, dimana serangan ini memanfaatkan sejumlah besar komputer untuk menjalankan serangan DoS kepada server, web service, atau sumber daya jaringan lain. Mengingat resiko besar yang diakibatkan serangan DDoS ini, banyak peneliti yang terdorong untuk merancang mekanisme penga-manan sumber daya jaringan. Pada penelitian ini, penulis mengkhususkan pokok permasalahan pada pengamanan web service. Penulis mengemuka-kan sebuah mekanisme untuk mengamankan web service dengan cara melakukan filtrasi dan validasi permintaan yang diterima untuk mengakses sumber daya jaringan. Filtrasi dan validasi ini dilakukan dengan gabungan metode Network Behavior Analysis (NBA dan Client Puzzle (CP. Metode NBA menjadi lapisan pertahanan pertama untuk mendeteksi apakah sedang terjadi serangan DDoS dengan mengukur tingkat kepadatan jaringan/Network density. Dari metode NBA, didapatkan IP Address yang perlu divalidasi dengan metode CP sebagai lapisan pertahanan kedua. Apabila suatu service request sudah berhasil melewati proses filtrasi dan validasi ini, maka service request ini baru akan dilayani. Dari hasil percobaan, terbukti metode ini dapat mendeteksi serangan DDoS sekaligus menjamin bahwa service request yang sah mendapat pelayanan yang seharusnya sehingga server dapat melayani service request dengan baik.

A Context-Aware Adaptive Streaming Media Distribution System in a Heterogeneous Network with Multiple Terminals

Directory of Open Access Journals (Sweden)

Yepeng Ni

2016-01-01

Full Text Available We consider the problem of streaming media transmission in a heterogeneous network from a multisource server to home multiple terminals. In wired network, the transmission performance is limited by network state (e.g., the bandwidth variation, jitter, and packet loss. In wireless network, the multiple user terminals can cause bandwidth competition. Thus, the streaming media distribution in a heterogeneous network becomes a severe challenge which is critical for QoS guarantee. In this paper, we propose a context-aware adaptive streaming media distribution system (CAASS, which implements the context-aware module to perceive the environment parameters and use the strategy analysis (SA module to deduce the most suitable service level. This approach is able to improve the video quality for guarantying streaming QoS. We formulate the optimization problem of QoS relationship with the environment parameters based on the QoS testing algorithm for IPTV in ITU-T G.1070. We evaluate the performance of the proposed CAASS through 12 types of experimental environments using a prototype system. Experimental results show that CAASS can dynamically adjust the service level according to the environment variation (e.g., network state and terminal performances and outperforms the existing streaming approaches in adaptive streaming media distribution according to peak signal-to-noise ratio (PSNR.

Kualitas Jaringan Pada Jaringan Virtual Local Area Network (VLAN Yang Menerapkan Linux Terminal Server Project (LTSP

Directory of Open Access Journals (Sweden)

Lipur Sugiyanta

2017-12-01

Full Text Available Virtual Local Area Network (VLAN merupakan sebuah teknik dalam jaringan komputer untuk menciptakan beberapa jaringan yang berbeda tetapi masih merupakan sebuah jaringan lokal yang tidak terbatas pada lokasi fisik seperti LAN sedangkan Linux Terminal Server Project (LTSP merupakan sebuah teknik terminal server yang dapat memperbanyak workstation dengan hanya menggunakan sebuah Linux server. Dalam membangun sebuah jaringan komputer perlu memperhatikan beberapa hal dan salah satunya adalah kualitas jaringan dari jaringan yang dibangun. Pada penelitian ini bertujuan untuk mengetahui pengaruh jumlah client terhadap kualitas jaringan berdasarkan parameter delay dan packet loss pada jaringan VLAN yang menerapkan LTSP. Oleh karena itu, penelitian ini menggunakan jenis metode penelitian kualitatif dengan memperhatikan standar yang digunakan dalam penelitian yaitu standar International Telecommunication Union – Telecommunication (ITU-T. Penerapan penelitian ini menggunakan sistem operasi pada server adalah Ubuntu Desktop 14.04 LTS. Berdasarkan dari hasil penelitian yang ditemukan dapat disimpulkan bahwa benar terbukti bahwa makin banyak client yang dilayani oleh server maka akan menurunkan kualitas jaringan berdasarkan parameter Quality of Service (QoS yang digunakan yaitu delay dan packet loss.

Improving data retrieval rates using remote data servers

International Nuclear Information System (INIS)

D'Ottavio, T.; Frak, B.; Nemesure, S.; Morris, J.

2012-01-01

The power and scope of modern Control Systems has led to an increased amount of data being collected and stored, including data collected at high (kHz) frequencies. One consequence is that users now routinely make data requests that can cause giga-bytes of data to be read and displayed. Given that a user's patience can be measured in seconds, this can be quite a technical challenge. This paper explores one possible solution to this problem - the creation of remote data servers whose performance is optimized to handle context-sensitive data requests. Methods for increasing data delivery performance include the use of high speed network connections between the stored data and the data servers, smart caching of frequently used data, and the culling of data delivered as determined by the context of the data request. This paper describes decisions made when constructing these servers and compares data retrieval performance by clients that use or do not use an intermediate data server. (authors)

BiFS-based approaches to remote display for mobile thin clients

Science.gov (United States)

Mitrea, M.; Simoens, P.; Joveski, B.; Marshall, J.; Taguengayte, A.; Prêteux, F.; Dhoed, B.

2009-08-01

Under the framework of the FP-7 European MobiThin project, the present study addresses the issue of remote display representation for mobile thin client. The main issue is to design a compressing algorithm for heterogeneous content (text, graphics, image and video) with low-complex decoding. As a first step in this direction, we propose a novel software architecture, based on BiFS - Binary Format for Scenes (MPEG-4 Part 11). On the server side, the graphical content is parsed, converted and binary encoded into the BiFS format. This content is then streamed to the terminal, where it is played on a simple MPEG player. The viability of this solution is validated by comparing it to the most intensively used wired solutions, e.g. VNC - Virtual Network Computing.

Solid Waste Information and Tracking System Server Conversion Project Management Plan

International Nuclear Information System (INIS)

GLASSCOCK, J.A.

2000-01-01

The Project Management Plan governing the conversion of SWITS to a client-server architecture. The PMP describes the background, planning and management of the SWITS conversion. Requirements and specification documentation needed for the SWITS conversion

The File Sync Algorithm of the ownCloud Desktop Clients

CERN Multimedia

CERN. Geneva

2014-01-01

The ownCloud desktop clients provide file syncing between desktop machines and the ownCloud server, available for the important desktop platforms. This presentation will give an overview of the sync algorithm used by the clients to provide a fast, reliable and robust syncing experience for the users. It will describe the phases a sync run will go through and how it is triggered. It also will provide an insight on the algorithms that decided if a file is uploaded, downloaded or even deleted on either on the local machine or in the cloud. Some examples of non obvious situations in file syncing will be described and discussed. As the ownCloud sync protocol is based on the open standard WebDAV the resulting challenges and the solutions will be illustrated. Finally a couple of frequently proposed enhancements will be reviewed and assed for the future development of the ownCloud server and syncing clients.

Hierarchical storage of large volume of multidector CT data using distributed servers

Science.gov (United States)

Ratib, Osman; Rosset, Antoine; Heuberger, Joris; Bandon, David

2006-03-01

Multidector scanners and hybrid multimodality scanners have the ability to generate large number of high-resolution images resulting in very large data sets. In most cases, these datasets are generated for the sole purpose of generating secondary processed images and 3D rendered images as well as oblique and curved multiplanar reformatted images. It is therefore not essential to archive the original images after they have been processed. We have developed an architecture of distributed archive servers for temporary storage of large image datasets for 3D rendering and image processing without the need for long term storage in PACS archive. With the relatively low cost of storage devices it is possible to configure these servers to hold several months or even years of data, long enough for allowing subsequent re-processing if required by specific clinical situations. We tested the latest generation of RAID servers provided by Apple computers with a capacity of 5 TBytes. We implemented a peer-to-peer data access software based on our Open-Source image management software called OsiriX, allowing remote workstations to directly access DICOM image files located on the server through a new technology called "bonjour". This architecture offers a seamless integration of multiple servers and workstations without the need for central database or complex workflow management tools. It allows efficient access to image data from multiple workstation for image analysis and visualization without the need for image data transfer. It provides a convenient alternative to centralized PACS architecture while avoiding complex and time-consuming data transfer and storage.

Mobile object retrieval in server-based image databases

Science.gov (United States)

Manger, D.; Pagel, F.; Widak, H.

2013-05-01

The increasing number of mobile phones equipped with powerful cameras leads to huge collections of user-generated images. To utilize the information of the images on site, image retrieval systems are becoming more and more popular to search for similar objects in an own image database. As the computational performance and the memory capacity of mobile devices are constantly increasing, this search can often be performed on the device itself. This is feasible, for example, if the images are represented with global image features or if the search is done using EXIF or textual metadata. However, for larger image databases, if multiple users are meant to contribute to a growing image database or if powerful content-based image retrieval methods with local features are required, a server-based image retrieval backend is needed. In this work, we present a content-based image retrieval system with a client server architecture working with local features. On the server side, the scalability to large image databases is addressed with the popular bag-of-word model with state-of-the-art extensions. The client end of the system focuses on a lightweight user interface presenting the most similar images of the database highlighting the visual information which is common with the query image. Additionally, new images can be added to the database making it a powerful and interactive tool for mobile contentbased image retrieval.

An Effective Distributed Model for Power System Transient Stability Analysis

Directory of Open Access Journals (Sweden)

MUTHU, B. M.

2011-08-01

Full Text Available The modern power systems consist of many interconnected synchronous generators having different inertia constants, connected with large transmission network and ever increasing demand for power exchange. The size of the power system grows exponentially due to increase in power demand. The data required for various power system applications have been stored in different formats in a heterogeneous environment. The power system applications themselves have been developed and deployed in different platforms and language paradigms. Interoperability between power system applications becomes a major issue because of the heterogeneous nature. The main aim of the paper is to develop a generalized distributed model for carrying out power system stability analysis. The more flexible and loosely coupled JAX-RPC model has been developed for representing transient stability analysis in large interconnected power systems. The proposed model includes Pre-Fault, During-Fault, Post-Fault and Swing Curve services which are accessible to the remote power system clients when the system is subjected to large disturbances. A generalized XML based model for data representation has also been proposed for exchanging data in order to enhance the interoperability between legacy power system applications. The performance measure, Round Trip Time (RTT is estimated for different power systems using the proposed JAX-RPC model and compared with the results obtained using traditional client-server and Java RMI models.

Implementation of news module for news client based on ApiCloud

OpenAIRE

Fu Xin; Liang Yu; Cao Sanxing; Gu Hongbo

2017-01-01

With the development of new media technology, news client has become the main battlefield of news browsing. Based on the ApiCloud hybrid development platform, this paper uses HTML, JavaScript and other technologies to develop the mobile client news module, and uses WAMP integrated development environment to build a news publishing system on the server side.

GlobAl Distribution of GEnetic Traits (GADGET) web server: polygenic trait scores worldwide.

Science.gov (United States)

Chande, Aroon T; Wang, Lu; Rishishwar, Lavanya; Conley, Andrew B; Norris, Emily T; Valderrama-Aguirre, Augusto; Jordan, I King

2018-05-18

Human populations from around the world show striking phenotypic variation across a wide variety of traits. Genome-wide association studies (GWAS) are used to uncover genetic variants that influence the expression of heritable human traits; accordingly, population-specific distributions of GWAS-implicated variants may shed light on the genetic basis of human phenotypic diversity. With this in mind, we developed the GlobAl Distribution of GEnetic Traits web server (GADGET http://gadget.biosci.gatech.edu). The GADGET web server provides users with a dynamic visual platform for exploring the relationship between worldwide genetic diversity and the genetic architecture underlying numerous human phenotypes. GADGET integrates trait-implicated single nucleotide polymorphisms (SNPs) from GWAS, with population genetic data from the 1000 Genomes Project, to calculate genome-wide polygenic trait scores (PTS) for 818 phenotypes in 2504 individual genomes. Population-specific distributions of PTS are shown for 26 human populations across 5 continental population groups, with traits ordered based on the extent of variation observed among populations. Users of GADGET can also upload custom trait SNP sets to visualize global PTS distributions for their own traits of interest.

Installing and Testing a Server Operating System

Directory of Open Access Journals (Sweden)

Lorentz JÄNTSCHI

2003-08-01

Full Text Available The paper is based on the experience of the author with the FreeBSD server operating system administration on three servers in use under academicdirect.ro domain.The paper describes a set of installation, preparation, and administration aspects of a FreeBSD server.First issue of the paper is the installation procedure of FreeBSD operating system on i386 computer architecture. Discussed problems are boot disks preparation and using, hard disk partitioning and operating system installation using a existent network topology and a internet connection.Second issue is the optimization procedure of operating system, server services installation, and configuration. Discussed problems are kernel and services configuration, system and services optimization.The third issue is about client-server applications. Using operating system utilities calls we present an original application, which allows displaying the system information in a friendly web interface. An original program designed for molecular structure analysis was adapted for systems performance comparisons and it serves for a discussion of Pentium, Pentium II and Pentium III processors computation speed.The last issue of the paper discusses the installation and configuration aspects of dial-in service on a UNIX-based operating system. The discussion includes serial ports, ppp and pppd services configuration, ppp and tun devices using.

Studying the co-evolution of protein families with the Mirrortree web server.

Science.gov (United States)

Ochoa, David; Pazos, Florencio

2010-05-15

The Mirrortree server allows to graphically and interactively study the co-evolution of two protein families, and investigate their possible interactions and functional relationships in a taxonomic context. The server includes the possibility of starting from single sequences and hence it can be used by non-expert users. The web server is freely available at http://csbg.cnb.csic.es/mtserver. It was tested in the main web browsers. Adobe Flash Player is required at the client side to perform the interactive assessment of co-evolution. pazos@cnb.csic.es Supplementary data are available at Bioinformatics online.

Thin Client Architecture: The Promise and the Problems.

Science.gov (United States)

Machovec, George S.

1997-01-01

Describes thin clients, a networking technology that allows organizations to provide software applications over networked workstations connected to a central server. Topics include corporate settings; major advantages, including cost effectiveness and increased computer security; problems; and possible applications for large public and academic…

Reusable Client-Side JavaScript Modules for Immersive Web-Based Real-Time Collaborative Neuroimage Visualization

Directory of Open Access Journals (Sweden)

Jorge L. Bernal-Rusiel

2017-05-01

Full Text Available In this paper we present a web-based software solution to the problem of implementing real-time collaborative neuroimage visualization. In both clinical and research settings, simple and powerful access to imaging technologies across multiple devices is becoming increasingly useful. Prior technical solutions have used a server-side rendering and push-to-client model wherein only the server has the full image dataset. We propose a rich client solution in which each client has all the data and uses the Google Drive Realtime API for state synchronization. We have developed a small set of reusable client-side object-oriented JavaScript modules that make use of the XTK toolkit, a popular open-source JavaScript library also developed by our team, for the in-browser rendering and visualization of brain image volumes. Efficient realtime communication among the remote instances is achieved by using just a small JSON object, comprising a representation of the XTK image renderers' state, as the Google Drive Realtime collaborative data model. The developed open-source JavaScript modules have already been instantiated in a web-app called MedView, a distributed collaborative neuroimage visualization application that is delivered to the users over the web without requiring the installation of any extra software or browser plugin. This responsive application allows multiple physically distant physicians or researchers to cooperate in real time to reach a diagnosis or scientific conclusion. It also serves as a proof of concept for the capabilities of the presented technological solution.

A real time multi-server multi-client coherent database for a new high voltage system

International Nuclear Information System (INIS)

Gorbics, M.; Green, M.

1995-01-01

A high voltage system has been designed to allow multiple users (clients) access to the database of measured values and settings. This database is actively maintained in real time for a given mainframe containing multiple modules each having their own database. With limited CPU nd memory resources the mainframe system provides a data coherency scheme for multiple clients which (1) allows the client to determine when and what values need to be updated, (2) allows for changes from one client to be detected by another client, and (3) does not depend on the mainframe system tracking client accesses

Implementation of news module for news client based on ApiCloud

Directory of Open Access Journals (Sweden)

Fu Xin

2017-01-01

Full Text Available With the development of new media technology, news client has become the main battlefield of news browsing. Based on the ApiCloud hybrid development platform, this paper uses HTML, JavaScript and other technologies to develop the mobile client news module, and uses WAMP integrated development environment to build a news publishing system on the server side.

A Capacity Supply Model for Virtualized Servers

Directory of Open Access Journals (Sweden)

Alexander PINNOW

2009-01-01

Full Text Available This paper deals with determining the capacity supply for virtualized servers. First, a server is modeled as a queue based on a Markov chain. Then, the effect of server virtualization on the capacity supply will be analyzed with the distribution function of the server load.

Automated Detection of Client-State Manipulation Vulnerabilities

DEFF Research Database (Denmark)

Møller, Anders; Schwarz, Mathias

2012-01-01

automated tools that can assist the programmers in the application development process by detecting weaknesses. Many vulnerabilities are related to web application code that stores references to application state in the generated HTML documents to work around the statelessness of the HTTP protocol....... In this paper, we show that such client-state manipulation vulnerabilities are amenable to tool supported detection. We present a static analysis for the widely used frameworks Java Servlets, JSP, and Struts. Given a web application archive as input, the analysis identifies occurrences of client state...... and infers the information flow between the client state and the shared application state on the server. This makes it possible to check how client-state manipulation performed by malicious users may affect the shared application state and cause leakage or modifications of sensitive information. The warnings...

Lsiviewer 2.0 - a Client-Oriented Online Visualization Tool for Geospatial Vector Data

Science.gov (United States)

Manikanta, K.; Rajan, K. S.

2017-09-01

Geospatial data visualization systems have been predominantly through applications that are installed and run in a desktop environment. Over the last decade, with the advent of web technologies and its adoption by Geospatial community, the server-client model for data handling, data rendering and visualization respectively has been the most prevalent approach in Web-GIS. While the client devices have become functionally more powerful over the recent years, the above model has largely ignored it and is still in a mode of serverdominant computing paradigm. In this paper, an attempt has been made to develop and demonstrate LSIViewer - a simple, easy-to-use and robust online geospatial data visualisation system for the user's own data that harness the client's capabilities for data rendering and user-interactive styling, with a reduced load on the server. The developed system can support multiple geospatial vector formats and can be integrated with other web-based systems like WMS, WFS, etc. The technology stack used to build this system is Node.js on the server side and HTML5 Canvas and JavaScript on the client side. Various tests run on a range of vector datasets, upto 35 MB, showed that the time taken to render the vector data using LSIViewer is comparable to a desktop GIS application, QGIS, over an identical system.

Distributed data collection for a database of radiological image interpretations

Science.gov (United States)

Long, L. Rodney; Ostchega, Yechiam; Goh, Gin-Hua; Thoma, George R.

1997-01-01

The National Library of Medicine, in collaboration with the National Center for Health Statistics and the National Institute for Arthritis and Musculoskeletal and Skin Diseases, has built a system for collecting radiological interpretations for a large set of x-ray images acquired as part of the data gathered in the second National Health and Nutrition Examination Survey. This system is capable of delivering across the Internet 5- and 10-megabyte x-ray images to Sun workstations equipped with X Window based 2048 X 2560 image displays, for the purpose of having these images interpreted for the degree of presence of particular osteoarthritic conditions in the cervical and lumbar spines. The collected interpretations can then be stored in a database at the National Library of Medicine, under control of the Illustra DBMS. This system is a client/server database application which integrates (1) distributed server processing of client requests, (2) a customized image transmission method for faster Internet data delivery, (3) distributed client workstations with high resolution displays, image processing functions and an on-line digital atlas, and (4) relational database management of the collected data.

E-mail security: mail clients must use encrypted protocols

CERN Multimedia

2006-01-01

In the coming weeks, users of mail clients other than Outlook (e.g. Pine, Mozilla, Mac Mail, etc.) may receive an e-mail from Mail-service@cern.ch with instructions to update the security settings of their mail client. The aim of this campaign is to enforce the use of encrypted and authenticated mail protocols in order to prevent the propagation of viruses and protect passwords from theft. As a first step, from 6 June 2006 onwards, access to mail servers from outside CERN will require a securely configured mail client as described in the help page http://cern.ch/mmmservices/Help/?kbid=191040. On this page most users will also find tools that will update their mail client settings automatically. Note that Outlook clients and WebMail access are not affected. The Mail Team

Queue Length and Server Content Distribution in an Infinite-Buffer Batch-Service Queue with Batch-Size-Dependent Service

Directory of Open Access Journals (Sweden)

U. C. Gupta

2015-01-01

Full Text Available We analyze an infinite-buffer batch-size-dependent batch-service queue with Poisson arrival and arbitrarily distributed service time. Using supplementary variable technique, we derive a bivariate probability generating function from which the joint distribution of queue and server content at departure epoch of a batch is extracted and presented in terms of roots of the characteristic equation. We also obtain the joint distribution of queue and server content at arbitrary epoch. Finally, the utility of analytical results is demonstrated by the inclusion of some numerical examples which also includes the investigation of multiple zeros.

MstApp, a rich client control applications framework at DESY

International Nuclear Information System (INIS)

Kirsten Hinsch, Winfried Schuette

2012-01-01

The control systems for PETRA 3 (a dedicated synchrotron machine) and its pre-accelerators extensively use rich clients for the control room and the servers. Most of them are written with the help of a rich client Java framework: MstApp. They totalize 106 different consoles and 158 individual server applications. MstApp takes care of many common control system application aspects beyond communication. MstApp provides a common look and feel: core menu items, a colour scheme for standard states of hardware components and predefined standardized screen sizes/locations. It interfaces our console application manager (CAM) and displays on demand our communication link diagnostics tools. MstApp supplies an accelerator context for each application; it handles printing, logging, re-sizing and unexpected application crashes. Due to our standardized deploy process MstApp applications know their individual developers and can even send them - on button press of the users - E-mails. Further a concept of different operation modes is implemented: view only, operating and expert use. Administration of the corresponding rights is done via web access of a database server. Initialization files on a web server are instantiated as JAVA objects with the help of the Java SE XML-Decoder. Data tables are read with the same mechanism. New MstApp applications can easily be created with in house wizards like the NewProjectWizard or the DeviceServerWizard. MstApp improves the operator experience, application developer productivity and delivered software quality. (authors)

Remote Laboratory Java Server Based on JACOB Project

Directory of Open Access Journals (Sweden)

Pavol Bisták

2011-02-01

Full Text Available Remote laboratories play an important role in the educational process of engineers. This paper deals with the structure of remote laboratories. The principle of the proposed remote laboratory structure is based on the Java server application that communicates with Matlab through the COM technology for the data exchange under the Windows operating system. Java does not support COM directly so the results of the JACOB project are used and modified to cope with this problem. In laboratories for control engineering education a control algorithm usually runs on a PC with Matlab that really controls the real plant. This is the server side described in the paper in details. To demonstrate the possibilities of a remote control a Java client server application is also introduced. It covers communication and offers a user friendly interface for the control of a remote plant and visualization of measured data.

Remote Sensing Data Analytics for Planetary Science with PlanetServer/EarthServer

Science.gov (United States)

Rossi, Angelo Pio; Figuera, Ramiro Marco; Flahaut, Jessica; Martinot, Melissa; Misev, Dimitar; Baumann, Peter; Pham Huu, Bang; Besse, Sebastien

2016-04-01

Planetary Science datasets, beyond the change in the last two decades from physical volumes to internet-accessible archives, still face the problem of large-scale processing and analytics (e.g. Rossi et al., 2014, Gaddis and Hare, 2015). PlanetServer, the Planetary Science Data Service of the EC-funded EarthServer-2 project (#654367) tackles the planetary Big Data analytics problem with an array database approach (Baumann et al., 2014). It is developed to serve a large amount of calibrated, map-projected planetary data online, mainly through Open Geospatial Consortium (OGC) Web Coverage Processing Service (WCPS) (e.g. Rossi et al., 2014; Oosthoek et al., 2013; Cantini et al., 2014). The focus of the H2020 evolution of PlanetServer is still on complex multidimensional data, particularly hyperspectral imaging and topographic cubes and imagery. In addition to hyperspectral and topographic from Mars (Rossi et al., 2014), the use of WCPS is applied to diverse datasets on the Moon, as well as Mercury. Other Solar System Bodies are going to be progressively available. Derived parameters such as summary products and indices can be produced through WCPS queries, as well as derived imagery colour combination products, dynamically generated and accessed also through OGC Web Coverage Service (WCS). Scientific questions translated into queries can be posed to a large number of individual coverages (data products), locally, regionally or globally. The new PlanetServer system uses the the Open Source Nasa WorldWind (e.g. Hogan, 2011) virtual globe as visualisation engine, and the array database Rasdaman Community Edition as core server component. Analytical tools and client components of relevance for multiple communities and disciplines are shared across service such as the Earth Observation and Marine Data Services of EarthServer. The Planetary Science Data Service of EarthServer is accessible on http://planetserver.eu. All its code base is going to be available on GitHub, on

JobCenter: an open source, cross-platform, and distributed job queue management system optimized for scalability and versatility

Directory of Open Access Journals (Sweden)

Jaschob Daniel

2012-07-01

Full Text Available Abstract Background Laboratories engaged in computational biology or bioinformatics frequently need to run lengthy, multistep, and user-driven computational jobs. Each job can tie up a computer for a few minutes to several days, and many laboratories lack the expertise or resources to build and maintain a dedicated computer cluster. Results JobCenter is a client–server application and framework for job management and distributed job execution. The client and server components are both written in Java and are cross-platform and relatively easy to install. All communication with the server is client-driven, which allows worker nodes to run anywhere (even behind external firewalls or “in the cloud” and provides inherent load balancing. Adding a worker node to the worker pool is as simple as dropping the JobCenter client files onto any computer and performing basic configuration, which provides tremendous ease-of-use, flexibility, and limitless horizontal scalability. Each worker installation may be independently configured, including the types of jobs it is able to run. Executed jobs may be written in any language and may include multistep workflows. Conclusions JobCenter is a versatile and scalable distributed job management system that allows laboratories to very efficiently distribute all computational work among available resources. JobCenter is freely available at http://code.google.com/p/jobcenter/.

Analisa Pemanfaatan Proxy Server Sebagai Media Filtering Dan Caching Pada Jaringan Komputer

OpenAIRE

-, Yuisar; Yulianti, Liza; H, Yanolanda Suzantri

2015-01-01

This research aims to Implement control and safe use of the internet at an agency with a utilization fee seminal may use the Linux operating system Ubuntu 14:04. Bandwidth division according to the time of busy servers and Internet client. To quick opening for the second time and so on. Blocking sites - porn site that tends to contain spyware. Accelerate video audio streaming. This study uses experimental research. In this study conducted experiments on the performance of the proxy server tha...

How to Configurate Oracle Enterprise Manager on Windows 2000 Server

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

Oracle Enterprise Manager is a system management tool, which provides an integrated solution for centrally managing your heterogeneous environment Servers. Enterprise Manager combines a graphical Console, Oracle Management Servers, Oracle Intelligent Agents, common services, and tools to provide an integrated, comprehensive systems management platform for managing Oracle products, and is comprised of such as Data

Display graphical information optimization methods in a client-server information system

Directory of Open Access Journals (Sweden)

Юрий Викторович Мазуревич

2015-07-01

Full Text Available This paper presents an approach to reduce load time and volume of data necessary to display web page due to server side preprocessing. Measurement of this approach’s effectivity has been conducted. There were discovered conditions in which this approach will be the most effective, its disadvantages and presented ways to reduce them

Time synchronization algorithm of distributed system based on server time-revise and workstation self-adjust

International Nuclear Information System (INIS)

Zhou Shumin; Sun Yamin; Tang Bin

2007-01-01

In order to enhance the time synchronization quality of the distributed system, a time synchronization algorithm of distributed system based on server time-revise and workstation self-adjust is proposed. The time-revise cycle and self-adjust process is introduced in the paper. The algorithm reduces network flow effectively and enhances the quality of clock-synchronization. (authors)

CCTOP: a Consensus Constrained TOPology prediction web server.

Science.gov (United States)

Dobson, László; Reményi, István; Tusnády, Gábor E

2015-07-01

The Consensus Constrained TOPology prediction (CCTOP; http://cctop.enzim.ttk.mta.hu) server is a web-based application providing transmembrane topology prediction. In addition to utilizing 10 different state-of-the-art topology prediction methods, the CCTOP server incorporates topology information from existing experimental and computational sources available in the PDBTM, TOPDB and TOPDOM databases using the probabilistic framework of hidden Markov model. The server provides the option to precede the topology prediction with signal peptide prediction and transmembrane-globular protein discrimination. The initial result can be recalculated by (de)selecting any of the prediction methods or mapped experiments or by adding user specified constraints. CCTOP showed superior performance to existing approaches. The reliability of each prediction is also calculated, which correlates with the accuracy of the per protein topology prediction. The prediction results and the collected experimental information are visualized on the CCTOP home page and can be downloaded in XML format. Programmable access of the CCTOP server is also available, and an example of client-side script is provided. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

JPIP proxy server with prefetching strategies based on user-navigation model and semantic map

OpenAIRE

Monteagudo Pereira, José Lino

2013-01-01

The efficient transmission of large resolution images and, in particular, the interactive transmission of images in a client-server scenario, is an important aspect for many applications. Among the current image compression standards, JPEG2000 excels for its interactive transmission capabilities. In general, three mechanisms are employed to optimize the transmission of images when using the JPEG2000 Interactive Protocol (JPIP): 1) packet re-sequencing at the server; 2) prefetching at the clie...

A Distributed Feature-based Environment for Collaborative Design

Directory of Open Access Journals (Sweden)

Wei-Dong Li

2003-02-01

Full Text Available This paper presents a client/server design environment based on 3D feature-based modelling and Java technologies to enable design information to be shared efficiently among members within a design team. In this environment, design tasks and clients are organised through working sessions generated and maintained by a collaborative server. The information from an individual design client during a design process is updated and broadcast to other clients in the same session through an event-driven and call-back mechanism. The downstream manufacturing analysis modules can be wrapped as agents and plugged into the open environment to support the design activities. At the server side, a feature-feature relationship is established and maintained to filter the varied information of a working part, so as to facilitate efficient information update during the design process.

Radiation monitoring system based on Internet

International Nuclear Information System (INIS)

Drndarevic, V.R.; Popovic, A.T; Bolic, M.D.; Pavlovic, R.S.

2001-01-01

This paper presents concept and realization of the modern distributed radiation monitoring system. The system uses existing conventional computer network and it is based on the standard Internet technology. One personal computer (PC) serves as host and system server, while a number of client computers, link to the server computer via standard local area network (LAN), are used as distributed measurement nodes. The interconnection between the server and clients are based on Transmission Control Protocol/Internet Protocol (TCP/IP). System software is based on server-client model. Based on this concept distributed system for gamma ray monitoring in the region of the Institute of Nuclear Sciences Vinca has been implemented. (author)

Preliminary investigations on TINI based distributed instrumentation systems

International Nuclear Information System (INIS)

Bezboruah, T.; Kalita, M.

2006-04-01

A prototype web enabled distributed instrumentation system is being proposed in the Department of Electronics Science, Gauhati University, Assam, India. The distributed instrumentation system contains sensors, legacy hardware, TCP/IP protocol converter, TCP/IP network Ethernet, Database Server, Web/Application Server and Client PCs. As part of the proposed work, Tiny Internet Interface (TINI, TBM390: Dallas Semiconductor) has been deployed as TCP/IP stack, and java programming language as software tools. A feature supported by Java, that is particularly relevant to the distributed system is its applet. An applet is a java class that can be downloaded from the web server and can be run in a context application such as web browser or an applet viewer. TINI has been installed as TCP/IP stack, as it is the best suited embedded system with java programming language and it has been uniquely designed for communicating over One Wire Devices (OWD) over network. Here we will discuss the hardware and software aspects of TINI with OWD for the present system. (author)

Analysis of free SSL/TLS Certificates and their implementation as Security Mechanism in Application Servers.

Directory of Open Access Journals (Sweden)

Mario E. Cueva Hurtado

2017-02-01

Full Text Available Security in the application layer (SSL, provides the confidentiality, integrity, and authenticity of the data, between two applications that communicate with each other. This article is the result of having implemented Free SSL / TLS Certificates in application servers, determining the relevant characteristics that must have a SSL/TLS certificate, the Certifying Authority generate it. A vulnerability analysis is developed in application servers and encrypted communications channel is established to protect against attacks such as man in the middle, phishing and maintaining the integrity of information that is transmitted between the client and server.

Secure data aggregation in heterogeneous and disparate networks using stand off server architecture

Science.gov (United States)

Vimalathithan, S.; Sudarsan, S. D.; Seker, R.; Lenin, R. B.; Ramaswamy, S.

2009-04-01

The emerging global reach of technology presents myriad challenges and intricacies as Information Technology teams aim to provide anywhere, anytime and anyone access, for service providers and customers alike. The world is fraught with stifling inequalities, both from an economic as well as socio-political perspective. The net result has been large capability gaps between various organizational locations that need to work together, which has raised new challenges for information security teams. Similar issues arise, when mergers and acquisitions among and between organizations take place. While integrating remote business locations with mainstream operations, one or more of the issues including the lack of application level support, computational capabilities, communication limitations, and legal requirements cause a serious impediment thereby complicating integration while not violating the organizations' security requirements. Often resorted techniques like IPSec, tunneling, secure socket layer, etc. may not be always techno-economically feasible. This paper addresses such security issues by introducing an intermediate server between corporate central server and remote sites, called stand-off-server. We present techniques such as break-before-make connection, break connection after transfer, multiple virtual machine instances with different operating systems using the concept of a stand-off-server. Our experiments show that the proposed solution provides sufficient isolation for the central server/site from attacks arising out of weak communication and/or computing links and is simple to implement.

LabKey Server: An open source platform for scientific data integration, analysis and collaboration

Science.gov (United States)

2011-01-01

Background Broad-based collaborations are becoming increasingly common among disease researchers. For example, the Global HIV Enterprise has united cross-disciplinary consortia to speed progress towards HIV vaccines through coordinated research across the boundaries of institutions, continents and specialties. New, end-to-end software tools for data and specimen management are necessary to achieve the ambitious goals of such alliances. These tools must enable researchers to organize and integrate heterogeneous data early in the discovery process, standardize processes, gain new insights into pooled data and collaborate securely. Results To meet these needs, we enhanced the LabKey Server platform, formerly known as CPAS. This freely available, open source software is maintained by professional engineers who use commercially proven practices for software development and maintenance. Recent enhancements support: (i) Submitting specimens requests across collaborating organizations (ii) Graphically defining new experimental data types, metadata and wizards for data collection (iii) Transitioning experimental results from a multiplicity of spreadsheets to custom tables in a shared database (iv) Securely organizing, integrating, analyzing, visualizing and sharing diverse data types, from clinical records to specimens to complex assays (v) Interacting dynamically with external data sources (vi) Tracking study participants and cohorts over time (vii) Developing custom interfaces using client libraries (viii) Authoring custom visualizations in a built-in R scripting environment. Diverse research organizations have adopted and adapted LabKey Server, including consortia within the Global HIV Enterprise. Atlas is an installation of LabKey Server that has been tailored to serve these consortia. It is in production use and demonstrates the core capabilities of LabKey Server. Atlas now has over 2,800 active user accounts originating from approximately 36 countries and 350

LabKey Server: An open source platform for scientific data integration, analysis and collaboration

Directory of Open Access Journals (Sweden)

Lum Karl

2011-03-01

Full Text Available Abstract Background Broad-based collaborations are becoming increasingly common among disease researchers. For example, the Global HIV Enterprise has united cross-disciplinary consortia to speed progress towards HIV vaccines through coordinated research across the boundaries of institutions, continents and specialties. New, end-to-end software tools for data and specimen management are necessary to achieve the ambitious goals of such alliances. These tools must enable researchers to organize and integrate heterogeneous data early in the discovery process, standardize processes, gain new insights into pooled data and collaborate securely. Results To meet these needs, we enhanced the LabKey Server platform, formerly known as CPAS. This freely available, open source software is maintained by professional engineers who use commercially proven practices for software development and maintenance. Recent enhancements support: (i Submitting specimens requests across collaborating organizations (ii Graphically defining new experimental data types, metadata and wizards for data collection (iii Transitioning experimental results from a multiplicity of spreadsheets to custom tables in a shared database (iv Securely organizing, integrating, analyzing, visualizing and sharing diverse data types, from clinical records to specimens to complex assays (v Interacting dynamically with external data sources (vi Tracking study participants and cohorts over time (vii Developing custom interfaces using client libraries (viii Authoring custom visualizations in a built-in R scripting environment. Diverse research organizations have adopted and adapted LabKey Server, including consortia within the Global HIV Enterprise. Atlas is an installation of LabKey Server that has been tailored to serve these consortia. It is in production use and demonstrates the core capabilities of LabKey Server. Atlas now has over 2,800 active user accounts originating from approximately 36

LabKey Server: an open source platform for scientific data integration, analysis and collaboration.

Science.gov (United States)

Nelson, Elizabeth K; Piehler, Britt; Eckels, Josh; Rauch, Adam; Bellew, Matthew; Hussey, Peter; Ramsay, Sarah; Nathe, Cory; Lum, Karl; Krouse, Kevin; Stearns, David; Connolly, Brian; Skillman, Tom; Igra, Mark

2011-03-09

Broad-based collaborations are becoming increasingly common among disease researchers. For example, the Global HIV Enterprise has united cross-disciplinary consortia to speed progress towards HIV vaccines through coordinated research across the boundaries of institutions, continents and specialties. New, end-to-end software tools for data and specimen management are necessary to achieve the ambitious goals of such alliances. These tools must enable researchers to organize and integrate heterogeneous data early in the discovery process, standardize processes, gain new insights into pooled data and collaborate securely. To meet these needs, we enhanced the LabKey Server platform, formerly known as CPAS. This freely available, open source software is maintained by professional engineers who use commercially proven practices for software development and maintenance. Recent enhancements support: (i) Submitting specimens requests across collaborating organizations (ii) Graphically defining new experimental data types, metadata and wizards for data collection (iii) Transitioning experimental results from a multiplicity of spreadsheets to custom tables in a shared database (iv) Securely organizing, integrating, analyzing, visualizing and sharing diverse data types, from clinical records to specimens to complex assays (v) Interacting dynamically with external data sources (vi) Tracking study participants and cohorts over time (vii) Developing custom interfaces using client libraries (viii) Authoring custom visualizations in a built-in R scripting environment. Diverse research organizations have adopted and adapted LabKey Server, including consortia within the Global HIV Enterprise. Atlas is an installation of LabKey Server that has been tailored to serve these consortia. It is in production use and demonstrates the core capabilities of LabKey Server. Atlas now has over 2,800 active user accounts originating from approximately 36 countries and 350 organizations. It tracks

(m, M) Machining system with two unreliable servers, mixed spares and common-cause failure

OpenAIRE

Jain, Madhu; Mittal, Ragini; Kumari, Rekha

2015-01-01

This paper deals with multi-component machine repair model having provision of warm standby units and repair facility consisting of two heterogeneous servers (primary and secondary) to provide repair to the failed units. The failure of operating and standby units may occur individually or due to some common cause. The primary server may fail partially following full failure whereas secondary server faces complete failure only. The life times of servers and operating/standby units and their re...

Effect of video server topology on contingency capacity requirements

Science.gov (United States)

Kienzle, Martin G.; Dan, Asit; Sitaram, Dinkar; Tetzlaff, William H.

1996-03-01

Video servers need to assign a fixed set of resources to each video stream in order to guarantee on-time delivery of the video data. If a server has insufficient resources to guarantee the delivery, it must reject the stream request rather than slowing down all existing streams. Large scale video servers are being built as clusters of smaller components, so as to be economical, scalable, and highly available. This paper uses a blocking model developed for telephone systems to evaluate video server cluster topologies. The goal is to achieve high utilization of the components and low per-stream cost combined with low blocking probability and high user satisfaction. The analysis shows substantial economies of scale achieved by larger server images. Simple distributed server architectures can result in partitioning of resources with low achievable resource utilization. By comparing achievable resource utilization of partitioned and monolithic servers, we quantify the cost of partitioning. Next, we present an architecture for a distributed server system that avoids resource partitioning and results in highly efficient server clusters. Finally, we show how, in these server clusters, further optimizations can be achieved through caching and batching of video streams.

The ABC Adaptive Fusion Architecture

DEFF Research Database (Denmark)

Bunde-Pedersen, Jonathan; Mogensen, Martin; Bardram, Jakob Eyvind

2006-01-01

Contemporary distributed collaborative systems tend to utilizeeither a client-server or a pure peer-to-peer paradigm. Aclient-server solution may potentially spawn direct connectionsbetween the clients to offload the server thereby creatinga hybrid architecture. A pure peer-to-peer paradigmmay on...

Design of Accelerator Online Simulator Server Using Structured Data

International Nuclear Information System (INIS)

Shen, Guobao

2012-01-01

Model based control plays an important role for a modern accelerator during beam commissioning, beam study, and even daily operation. With a realistic model, beam behaviour can be predicted and therefore effectively controlled. The approach used by most current high level application environments is to use a built-in simulation engine and feed a realistic model into that simulation engine. Instead of this traditional monolithic structure, a new approach using a client-server architecture is under development. An on-line simulator server is accessed via network accessible structured data. With this approach, a user can easily access multiple simulation codes. This paper describes the design, implementation, and current status of PVData, which defines the structured data, and PVAccess, which provides network access to the structured data.

Solid waste information and tracking system server conversion project management plan

International Nuclear Information System (INIS)

MAY, D.L.

1999-01-01

The Project Management Plan governing the conversion of Solid Waste Information and Tracking System (SWITS) to a client-server architecture. The Solid Waste Information and Tracking System Project Management Plan (PMP) describes the background, planning and management of the SWITS conversion. Requirements and specification documentation needed for the SWITS conversion will be released as supporting documents

Locating Hidden Servers

National Research Council Canada - National Science Library

Oeverlier, Lasse; Syverson, Paul F

2006-01-01

.... Announced properties include server resistance to distributed DoS. Both the EFF and Reporters Without Borders have issued guides that describe using hidden services via Tor to protect the safety of dissidents as well as to resist censorship...

DelPhiPKa web server: predicting pKa of proteins, RNAs and DNAs.

Science.gov (United States)

Wang, Lin; Zhang, Min; Alexov, Emil

2016-02-15

A new pKa prediction web server is released, which implements DelPhi Gaussian dielectric function to calculate electrostatic potentials generated by charges of biomolecules. Topology parameters are extended to include atomic information of nucleotides of RNA and DNA, which extends the capability of pKa calculations beyond proteins. The web server allows the end-user to protonate the biomolecule at particular pH based on calculated pKa values and provides the downloadable file in PQR format. Several tests are performed to benchmark the accuracy and speed of the protocol. The web server follows a client-server architecture built on PHP and HTML and utilizes DelPhiPKa program. The computation is performed on the Palmetto supercomputer cluster and results/download links are given back to the end-user via http protocol. The web server takes advantage of MPI parallel implementation in DelPhiPKa and can run a single job on up to 24 CPUs. The DelPhiPKa web server is available at http://compbio.clemson.edu/pka_webserver. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Distributed Monitoring System Based on ICINGA

CERN Multimedia

Haen, C; Neufeld, N

2011-01-01

The LHCb online system relies on a large and heterogeneous I.T. infrastructure : it comprises more than 2000 servers and embedded systems and more than 200 network devices. While for the control and monitoring of detectors, PLCs, and readout boards an industry standard SCADA system PVSSII has been put in production, we use a low level monitoring system to monitor the control infrastructure itself. While our previous system was based on a single central NAGIOS server, our current system uses a distributed ICINGA infrastructure.

TBI server: a web server for predicting ion effects in RNA folding.

Science.gov (United States)

Zhu, Yuhong; He, Zhaojian; Chen, Shi-Jie

2015-01-01

Metal ions play a critical role in the stabilization of RNA structures. Therefore, accurate prediction of the ion effects in RNA folding can have a far-reaching impact on our understanding of RNA structure and function. Multivalent ions, especially Mg²⁺, are essential for RNA tertiary structure formation. These ions can possibly become strongly correlated in the close vicinity of RNA surface. Most of the currently available software packages, which have widespread success in predicting ion effects in biomolecular systems, however, do not explicitly account for the ion correlation effect. Therefore, it is important to develop a software package/web server for the prediction of ion electrostatics in RNA folding by including ion correlation effects. The TBI web server http://rna.physics.missouri.edu/tbi_index.html provides predictions for the total electrostatic free energy, the different free energy components, and the mean number and the most probable distributions of the bound ions. A novel feature of the TBI server is its ability to account for ion correlation and ion distribution fluctuation effects. By accounting for the ion correlation and fluctuation effects, the TBI server is a unique online tool for computing ion-mediated electrostatic properties for given RNA structures. The results can provide important data for in-depth analysis for ion effects in RNA folding including the ion-dependence of folding stability, ion uptake in the folding process, and the interplay between the different energetic components.

TBI server: a web server for predicting ion effects in RNA folding.

Directory of Open Access Journals (Sweden)

Yuhong Zhu

Full Text Available Metal ions play a critical role in the stabilization of RNA structures. Therefore, accurate prediction of the ion effects in RNA folding can have a far-reaching impact on our understanding of RNA structure and function. Multivalent ions, especially Mg²⁺, are essential for RNA tertiary structure formation. These ions can possibly become strongly correlated in the close vicinity of RNA surface. Most of the currently available software packages, which have widespread success in predicting ion effects in biomolecular systems, however, do not explicitly account for the ion correlation effect. Therefore, it is important to develop a software package/web server for the prediction of ion electrostatics in RNA folding by including ion correlation effects.The TBI web server http://rna.physics.missouri.edu/tbi_index.html provides predictions for the total electrostatic free energy, the different free energy components, and the mean number and the most probable distributions of the bound ions. A novel feature of the TBI server is its ability to account for ion correlation and ion distribution fluctuation effects.By accounting for the ion correlation and fluctuation effects, the TBI server is a unique online tool for computing ion-mediated electrostatic properties for given RNA structures. The results can provide important data for in-depth analysis for ion effects in RNA folding including the ion-dependence of folding stability, ion uptake in the folding process, and the interplay between the different energetic components.

Measuring the effects of heterogeneity on distributed systems

Science.gov (United States)

El-Toweissy, Mohamed; Zeineldine, Osman; Mukkamala, Ravi

1991-01-01

Distributed computer systems in daily use are becoming more and more heterogeneous. Currently, much of the design and analysis studies of such systems assume homogeneity. This assumption of homogeneity has been mainly driven by the resulting simplicity in modeling and analysis. A simulation study is presented which investigated the effects of heterogeneity on scheduling algorithms for hard real time distributed systems. In contrast to previous results which indicate that random scheduling may be as good as a more complex scheduler, this algorithm is shown to be consistently better than a random scheduler. This conclusion is more prevalent at high workloads as well as at high levels of heterogeneity.

CMS distributed data analysis with CRAB3

Science.gov (United States)

Mascheroni, M.; Balcas, J.; Belforte, S.; Bockelman, B. P.; Hernandez, J. M.; Ciangottini, D.; Konstantinov, P. B.; Silva, J. M. D.; Ali, M. A. B. M.; Melo, A. M.; Riahi, H.; Tanasijczuk, A. J.; Yusli, M. N. B.; Wolf, M.; Woodard, A. E.; Vaandering, E.

2015-12-01

The CMS Remote Analysis Builder (CRAB) is a distributed workflow management tool which facilitates analysis tasks by isolating users from the technical details of the Grid infrastructure. Throughout LHC Run 1, CRAB has been successfully employed by an average of 350 distinct users each week executing about 200,000 jobs per day. CRAB has been significantly upgraded in order to face the new challenges posed by LHC Run 2. Components of the new system include 1) a lightweight client, 2) a central primary server which communicates with the clients through a REST interface, 3) secondary servers which manage user analysis tasks and submit jobs to the CMS resource provisioning system, and 4) a central service to asynchronously move user data from temporary storage in the execution site to the desired storage location. The new system improves the robustness, scalability and sustainability of the service. Here we provide an overview of the new system, operation, and user support, report on its current status, and identify lessons learned from the commissioning phase and production roll-out.

"MedTRIS" (Medical Triage and Registration Informatics System): A Web-based Client Server System for the Registration of Patients Being Treated in First Aid Posts at Public Events and Mass Gatherings.

Science.gov (United States)

Gogaert, Stefan; Vande Veegaete, Axel; Scholliers, Annelies; Vandekerckhove, Philippe

2016-10-01

First aid (FA) services are provisioned on-site as a preventive measure at most public events. In Flanders, Belgium, the Belgian Red Cross-Flanders (BRCF) is the major provider of these FA services with volunteers being deployed at approximately 10,000 public events annually. The BRCF has systematically registered information on the patients being treated in FA posts at major events and mass gatherings during the last 10 years. This information has been collected in a web-based client server system called "MedTRIS" (Medical Triage and Registration Informatics System). MedTRIS contains data on more than 200,000 patients at 335 mass events. This report describes the MedTRIS architecture, the data collected, and how the system operates in the field. This database consolidates different types of information with regards to FA interventions in a standardized way for a variety of public events. MedTRIS allows close monitoring in "real time" of the situation at mass gatherings and immediate intervention, when necessary; allows more accurate prediction of resources needed; allows to validate conceptual and predictive models for medical resources at (mass) public events; and can contribute to the definition of a standardized minimum data set (MDS) for mass-gathering health research and evaluation. Gogaert S , Vande veegaete A , Scholliers A , Vandekerckhove P . "MedTRIS" (Medical Triage and Registration Informatics System): a web-based client server system for the registration of patients being treated in first aid posts at public events and mass gatherings. Prehosp Disaster Med. 2016;31(5):557-562.

High-Performance Tiled WMS and KML Web Server

Science.gov (United States)

Plesea, Lucian

2007-01-01

This software is an Apache 2.0 module implementing a high-performance map server to support interactive map viewers and virtual planet client software. It can be used in applications that require access to very-high-resolution geolocated images, such as GIS, virtual planet applications, and flight simulators. It serves Web Map Service (WMS) requests that comply with a given request grid from an existing tile dataset. It also generates the KML super-overlay configuration files required to access the WMS image tiles.

The RNAsnp web server

DEFF Research Database (Denmark)

Radhakrishnan, Sabarinathan; Tafer, Hakim; Seemann, Ernst Stefan

2013-01-01

, are derived from extensive pre-computed tables of distributions of substitution effects as a function of gene length and GC content. Here, we present a web service that not only provides an interface for RNAsnp but also features a graphical output representation. In addition, the web server is connected...... to a local mirror of the UCSC genome browser database that enables the users to select the genomic sequences for analysis and visualize the results directly in the UCSC genome browser. The RNAsnp web server is freely available at: http://rth.dk/resources/rnasnp/....

A polling model with an autonomous server

NARCIS (Netherlands)

de Haan, Roland; Boucherie, Richardus J.; van Ommeren, Jan C.W.

2009-01-01

This paper considers polling systems with an autonomous server that remain at a queue for an exponential amount of time before moving to a next queue incurring a generally distributed switch-over time. The server remains at a queue until the exponential visit time expires, also when the queue

Effect of Heterogeneity in Initial Geographic Distribution on Opinions’ Competitiveness

Directory of Open Access Journals (Sweden)

Alexander S. Balankin

2015-05-01

Full Text Available Spin dynamics on networks allows us to understand how a global consensus emerges out of individual opinions. Here, we are interested in the effect of heterogeneity in the initial geographic distribution of a competing opinion on the competitiveness of its own opinion. Accordingly, in this work, we studied the effect of spatial heterogeneity on the majority rule dynamics using a three-state spin model, in which one state is neutral. Monte Carlo simulations were performed on square lattices divided into square blocks (cells. Accordingly, one competing opinion was distributed uniformly among cells, whereas the spatial distribution of the rival opinion was varied from the uniform to heterogeneous, with the median-to-mean ratio in the range from 1 to 0. When the size of discussion group is odd, the uncommitted agents disappear completely after  3.30 ± 0.05 update cycles, and then the system evolves in a two-state regime with complementary spatial distributions of two competing opinions. Even so, the initial heterogeneity in the spatial distribution of one of the competing opinions causes a decrease of this opinion competitiveness. That is, the opinion with initially heterogeneous spatial distribution has less probability to win, than the opinion with the initially uniform spatial distribution, even when the initial concentrations of both opinions are equal. We found that although the time to consensus , the opinion’s recession rate is determined during the first 3.3 update cycles. On the other hand, we found that the initial heterogeneity of the opinion spatial distribution assists the formation of quasi-stable regions, in which this opinion is dominant. The results of Monte Carlo simulations are discussed with regard to the electoral competition of political parties.

Online characterization of planetary surfaces: PlanetServer, an open-source analysis and visualization tool

Science.gov (United States)

Marco Figuera, R.; Pham Huu, B.; Rossi, A. P.; Minin, M.; Flahaut, J.; Halder, A.

2018-01-01

The lack of open-source tools for hyperspectral data visualization and analysis creates a demand for new tools. In this paper we present the new PlanetServer, a set of tools comprising a web Geographic Information System (GIS) and a recently developed Python Application Programming Interface (API) capable of visualizing and analyzing a wide variety of hyperspectral data from different planetary bodies. Current WebGIS open-source tools are evaluated in order to give an overview and contextualize how PlanetServer can help in this matters. The web client is thoroughly described as well as the datasets available in PlanetServer. Also, the Python API is described and exposed the reason of its development. Two different examples of mineral characterization of different hydrosilicates such as chlorites, prehnites and kaolinites in the Nili Fossae area on Mars are presented. As the obtained results show positive outcome in hyperspectral analysis and visualization compared to previous literature, we suggest using the PlanetServer approach for such investigations.

On a Batch Arrival Queuing System Equipped with a Stand-by Server during Vacation Periods or the Repairs Times of the Main Server

Directory of Open Access Journals (Sweden)

Rehab F. Khalaf

2011-01-01

Full Text Available We study a queuing system which is equipped with a stand-by server in addition to the main server. The stand-by server provides service to customers only during the period of absence of the main server when either the main server is on a vacation or it is in the state of repairs due to a sudden failure from time to time. The service times, vacation times, and repair times are assumed to follow general arbitrary distributions while the stand-by service times follow exponential distribution. Supplementary variables technique has been used to obtain steady state results in explicit and closed form in terms of the probability generating functions for the number of customers in the queue, the average number of customers, and the average waiting time in the queue while the MathCad software has been used to illustrate the numerical results in this work.

From honeybees to Internet servers: biomimicry for distributed management of Internet hosting centers.

Science.gov (United States)

Nakrani, Sunil; Tovey, Craig

2007-12-01

An Internet hosting center hosts services on its server ensemble. The center must allocate servers dynamically amongst services to maximize revenue earned from hosting fees. The finite server ensemble, unpredictable request arrival behavior and server reallocation cost make server allocation optimization difficult. Server allocation closely resembles honeybee forager allocation amongst flower patches to optimize nectar influx. The resemblance inspires a honeybee biomimetic algorithm. This paper describes details of the honeybee self-organizing model in terms of information flow and feedback, analyzes the homology between the two problems and derives the resulting biomimetic algorithm for hosting centers. The algorithm is assessed for effectiveness and adaptiveness by comparative testing against benchmark and conventional algorithms. Computational results indicate that the new algorithm is highly adaptive to widely varying external environments and quite competitive against benchmark assessment algorithms. Other swarm intelligence applications are briefly surveyed, and some general speculations are offered regarding their various degrees of success.

Heterogeneous Distribution of Chromium on Mercury

Science.gov (United States)

Nittler, L. R.; Boujibar, A.; Crapster-Pregont, E.; Frank, E. A.; McCoy, T. J.; McCubbin, F. M.; Starr, R. D.; Vander Kaaden, K. E.; Vorburger, A.; Weider, S. Z.

2018-05-01

Mercury's surface has an average Cr/Si ratio of 0.003 (Cr 800 ppm), with at least a factor of 2 systematic uncertainty. Cr is heterogeneously distributed and correlated with Mg, Ca, S, and Fe and anti-correlated with Al.

Heterogeneous game resource distributions promote cooperation in spatial prisoner's dilemma game

Science.gov (United States)

Cui, Guang-Hai; Wang, Zhen; Yang, Yan-Cun; Tian, Sheng-Wen; Yue, Jun

2018-01-01

In social networks, individual abilities to establish interactions are always heterogeneous and independent of the number of topological neighbors. We here study the influence of heterogeneous distributions of abilities on the evolution of individual cooperation in the spatial prisoner's dilemma game. First, we introduced a prisoner's dilemma game, taking into account individual heterogeneous abilities to establish games, which are determined by the owned game resources. Second, we studied three types of game resource distributions that follow the power-law property. Simulation results show that the heterogeneous distribution of individual game resources can promote cooperation effectively, and the heterogeneous level of resource distributions has a positive influence on the maintenance of cooperation. Extensive analysis shows that cooperators with large resource capacities can foster cooperator clusters around themselves. Furthermore, when the temptation to defect is high, cooperator clusters in which the central pure cooperators have larger game resource capacities are more stable than other cooperator clusters.

Web-Based Distributed Simulation of Aeronautical Propulsion System

Science.gov (United States)

Zheng, Desheng; Follen, Gregory J.; Pavlik, William R.; Kim, Chan M.; Liu, Xianyou; Blaser, Tammy M.; Lopez, Isaac

2001-01-01

An application was developed to allow users to run and view the Numerical Propulsion System Simulation (NPSS) engine simulations from web browsers. Simulations were performed on multiple INFORMATION POWER GRID (IPG) test beds. The Common Object Request Broker Architecture (CORBA) was used for brokering data exchange among machines and IPG/Globus for job scheduling and remote process invocation. Web server scripting was performed by JavaServer Pages (JSP). This application has proven to be an effective and efficient way to couple heterogeneous distributed components.

KeyWare: an open wireless distributed computing environment

Science.gov (United States)

Shpantzer, Isaac; Schoenfeld, Larry; Grindahl, Merv; Kelman, Vladimir

1995-12-01

Deployment of distributed applications in the wireless domain lack equivalent tools, methodologies, architectures, and network management that exist in LAN based applications. A wireless distributed computing environment (KeyWareTM) based on intelligent agents within a multiple client multiple server scheme was developed to resolve this problem. KeyWare renders concurrent application services to wireline and wireless client nodes encapsulated in multiple paradigms such as message delivery, database access, e-mail, and file transfer. These services and paradigms are optimized to cope with temporal and spatial radio coverage, high latency, limited throughput and transmission costs. A unified network management paradigm for both wireless and wireline facilitates seamless extensions of LAN- based management tools to include wireless nodes. A set of object oriented tools and methodologies enables direct asynchronous invocation of agent-based services supplemented by tool-sets matched to supported KeyWare paradigms. The open architecture embodiment of KeyWare enables a wide selection of client node computing platforms, operating systems, transport protocols, radio modems and infrastructures while maintaining application portability.

BioconductorBuntu: a Linux distribution that implements a web-based DNA microarray analysis server.

Science.gov (United States)

Geeleher, Paul; Morris, Dermot; Hinde, John P; Golden, Aaron

2009-06-01

BioconductorBuntu is a custom distribution of Ubuntu Linux that automatically installs a server-side microarray processing environment, providing a user-friendly web-based GUI to many of the tools developed by the Bioconductor Project, accessible locally or across a network. System installation is via booting off a CD image or by using a Debian package provided to upgrade an existing Ubuntu installation. In its current version, several microarray analysis pipelines are supported including oligonucleotide, dual-or single-dye experiments, including post-processing with Gene Set Enrichment Analysis. BioconductorBuntu is designed to be extensible, by server-side integration of further relevant Bioconductor modules as required, facilitated by its straightforward underlying Python-based infrastructure. BioconductorBuntu offers an ideal environment for the development of processing procedures to facilitate the analysis of next-generation sequencing datasets. BioconductorBuntu is available for download under a creative commons license along with additional documentation and a tutorial from (http://bioinf.nuigalway.ie).

A remote tracing facility for distributed systems

International Nuclear Information System (INIS)

Ehm, F.; Dworak, A.

2012-01-01

Today, CERN's control system is built upon a large number of C++ and Java services producing log events. In such a largely distributed environment these log messages are essential for problem recognition and tracing. Tracing is therefore vital for operation as understanding an issue in a subsystem means analysing log events in an efficient and fast manner. At present 3150 device servers are deployed on 1600 disk-less front-ends and they send their log messages via the network to an in-house developed central server which, in turn, saves them to files. However, this solution is not able to provide several highly desired features and has performance limitations which led to the development of a new solution. The new distributed tracing facility fulfills these requirements by taking advantage of the Streaming Text Oriented Messaging Protocol (STOMP) and ActiveMQ as the transport layer. The system not only allows storing critical log events centrally in files or in a database but also allows other clients (e.g. graphical interfaces) to read the same events concurrently by using the provided Java API. Thanks to the ActiveMQ broker technology the system can easily be extended to clients implemented in other languages and it is highly scalable in terms of performance. Long running tests have shown that the system can handle up to 10.000 messages/second. (authors)

Analisis Perbandingan Load Balancing Web Server Tunggal Dengan Web Server Cluster Menggunakan Linux Virtual Server

OpenAIRE

Lukitasari, Desy; Oklilas, Ahmad Fali

2010-01-01

Virtual server adalah server yang mempunyai skalabilitas dan ketersedian yang tinggi yang dibangun diatas sebuah cluster dari beberapa real server. Real server dan load balancer akan saling terkoneksi baik dalam jaringan lokal kecepatan tinggi atau yang terpisah secara geografis. Load balancer dapat mengirim permintaan-permintaan ke server yang berbeda dan membuat paralel service dari sebuah cluster pada sebuah alamat IP tunggal dan meminta pengiriman dapat menggunakan teknologi IP load...

Scheduling in Heterogeneous Grid Environments: The Effects of DataMigration

Energy Technology Data Exchange (ETDEWEB)

Oliker, Leonid; Biswas, Rupak; Shan, Hongzhang; Smith, Warren

2004-01-01

Computational grids have the potential for solving large-scale scientific problems using heterogeneous and geographically distributed resources. However, a number of major technical hurdles must be overcome before this goal can be fully realized. One problem critical to the effective utilization of computational grids is efficient job scheduling. Our prior work addressed this challenge by defining a grid scheduling architecture and several job migration strategies. The focus of this study is to explore the impact of data migration under a variety of demanding grid conditions. We evaluate our grid scheduling algorithms by simulating compute servers, various groupings of servers into sites, and inter-server networks, using real workloads obtained from leading supercomputing centers. Several key performance metrics are used to compare the behavior of our algorithms against reference local and centralized scheduling schemes. Results show the tremendous benefits of grid scheduling, even in the presence of input/output data migration - while highlighting the importance of utilizing communication-aware scheduling schemes.

A distributed scheduling algorithm for heterogeneous real-time systems

Science.gov (United States)

Zeineldine, Osman; El-Toweissy, Mohamed; Mukkamala, Ravi

1991-01-01

Much of the previous work on load balancing and scheduling in distributed environments was concerned with homogeneous systems and homogeneous loads. Several of the results indicated that random policies are as effective as other more complex load allocation policies. The effects of heterogeneity on scheduling algorithms for hard real time systems is examined. A distributed scheduler specifically to handle heterogeneities in both nodes and node traffic is proposed. The performance of the algorithm is measured in terms of the percentage of jobs discarded. While a random task allocation is very sensitive to heterogeneities, the algorithm is shown to be robust to such non-uniformities in system components and load.

PoD: dynamically create and use remote PROOF clusters. A thin client concept.

CERN Multimedia

CERN. Geneva

2012-01-01

PoD’s newly developed “pod-remote” command made it possible for users to utilize a thin client concept. In order to create dynamic PROOF clusters, users are now able to select a remote computer, even behind a firewall, to control a PoD server on...

Integrating CLIPS applications into heterogeneous distributed systems

Science.gov (United States)

Adler, Richard M.

1991-01-01

SOCIAL is an advanced, object-oriented development tool for integrating intelligent and conventional applications across heterogeneous hardware and software platforms. SOCIAL defines a family of 'wrapper' objects called agents, which incorporate predefined capabilities for distributed communication and control. Developers embed applications within agents and establish interactions between distributed agents via non-intrusive message-based interfaces. This paper describes a predefined SOCIAL agent that is specialized for integrating C Language Integrated Production System (CLIPS)-based applications. The agent's high-level Application Programming Interface supports bidirectional flow of data, knowledge, and commands to other agents, enabling CLIPS applications to initiate interactions autonomously, and respond to requests and results from heterogeneous remote systems. The design and operation of CLIPS agents are illustrated with two distributed applications that integrate CLIPS-based expert systems with other intelligent systems for isolating and mapping problems in the Space Shuttle Launch Processing System at the NASA Kennedy Space Center.

PENERAPAN ARSITEKTUR MULTI-TIER DENGAN DCOM DALAM SUATU SISTEM INFORMASI

Directory of Open Access Journals (Sweden)

Kartika Gunadi

2001-01-01

Full Text Available Information System implementation using two-tier architecture result lack in several critical issues : reuse component, scalability, maintenance, and data security. The multi-tiered client/server architecture provides a good resolution to solve these problems that using DCOM technology . The software is made by using Delphi 4 Client/Server Suite and Microsoft SQL Server V. 7.0 as a database server software. The multi-tiered application is partitioned into thirds. The first is client application which provides presentation services. The second is server application which provides application services, and the third is database server which provides database services. This multi-tiered application software can be made in two model. They are Client/Server Windows model and Client/Server Web model with ActiveX Form Technology. In this research is found that making multi-tiered architecture with using DCOM technology can provide many benefits such as, centralized application logic in middle-tier, make thin client application, distributed load of data process in several machines, increases security with the ability in hiding data, dan fast maintenance without installing database drivers in every client. Abstract in Bahasa Indonesia : Penerapan sistem informasi menggunakan two-tier architecture mempunyai banyak kelemahan : penggunaan kembali komponen, skalabilitas, perawatan, dan keamanan data. Multi-tier Client-Server architecture mempunyai kemampuan untuk memecahkan masalah ini dengan DCOM teknologi. Perangkat lunak ini dapat dibuat menggunakan Delphi 4 Client/Server Suite dan Microsoft SQL Server 7.0 sebagai perangkat lunak database. Aplikasi program multi-tier ini dibagi menjadi tiga partisi. Pertama adalah aplikasi client menyediakan presentasi servis, kedua aplikasi server menyediakan servis aplikasi, dan ketiga aplikasi database menyediakan database servis. Perangkat lunak aplikasi multi-tier ini dapat dibuat dalam dua model, yaitu client/server

Towards synergy between learning management systems and educational server applications

OpenAIRE

Hartog, R.J.M.; Schaaf, van der, H.; Kassahun, A.

2008-01-01

Most well-known Learning Management Systems (LMS) are based on a paradigm of learning objects to be uploaded into the system. Most formulations of this paradigm implicitly assume that the learning objects are self contained learning objects such as FLASH objects or JAVA applets or presentational learning objects such as slide presentations. These are typically client side objects. However, a demand for learning support that activates the student can often be satisfied better with a server app...

Research on distributed heterogeneous data PCA algorithm based on cloud platform

Science.gov (United States)

Zhang, Jin; Huang, Gang

2018-05-01

Principal component analysis (PCA) of heterogeneous data sets can solve the problem that centralized data scalability is limited. In order to reduce the generation of intermediate data and error components of distributed heterogeneous data sets, a principal component analysis algorithm based on heterogeneous data sets under cloud platform is proposed. The algorithm performs eigenvalue processing by using Householder tridiagonalization and QR factorization to calculate the error component of the heterogeneous database associated with the public key to obtain the intermediate data set and the lost information. Experiments on distributed DBM heterogeneous datasets show that the model method has the feasibility and reliability in terms of execution time and accuracy.

The architecture of a virtual grid GIS server

Science.gov (United States)

Wu, Pengfei; Fang, Yu; Chen, Bin; Wu, Xi; Tian, Xiaoting

2008-10-01

The grid computing technology provides the service oriented architecture for distributed applications. The virtual Grid GIS server is the distributed and interoperable enterprise application GIS architecture running in the grid environment, which integrates heterogeneous GIS platforms. All sorts of legacy GIS platforms join the grid as members of GIS virtual organization. Based on Microkernel we design the ESB and portal GIS service layer, which compose Microkernel GIS. Through web portals, portal GIS services and mediation of service bus, following the principle of SoC, we separate business logic from implementing logic. Microkernel GIS greatly reduces the coupling degree between applications and GIS platforms. The enterprise applications are independent of certain GIS platforms, and making the application developers to pay attention to the business logic. Via configuration and orchestration of a set of fine-grained services, the system creates GIS Business, which acts as a whole WebGIS request when activated. In this way, the system satisfies a business workflow directly and simply, with little or no new code.

An Array Library for Microsoft SQL Server with Astrophysical Applications

Science.gov (United States)

Dobos, L.; Szalay, A. S.; Blakeley, J.; Falck, B.; Budavári, T.; Csabai, I.

2012-09-01

Today's scientific simulations produce output on the 10-100 TB scale. This unprecedented amount of data requires data handling techniques that are beyond what is used for ordinary files. Relational database systems have been successfully used to store and process scientific data, but the new requirements constantly generate new challenges. Moving terabytes of data among servers on a timely basis is a tough problem, even with the newest high-throughput networks. Thus, moving the computations as close to the data as possible and minimizing the client-server overhead are absolutely necessary. At least data subsetting and preprocessing have to be done inside the server process. Out of the box commercial database systems perform very well in scientific applications from the prospective of data storage optimization, data retrieval, and memory management but lack basic functionality like handling scientific data structures or enabling advanced math inside the database server. The most important gap in Microsoft SQL Server is the lack of a native array data type. Fortunately, the technology exists to extend the database server with custom-written code that enables us to address these problems. We present the prototype of a custom-built extension to Microsoft SQL Server that adds array handling functionality to the database system. With our Array Library, fix-sized arrays of all basic numeric data types can be created and manipulated efficiently. Also, the library is designed to be able to be seamlessly integrated with the most common math libraries, such as BLAS, LAPACK, FFTW, etc. With the help of these libraries, complex operations, such as matrix inversions or Fourier transformations, can be done on-the-fly, from SQL code, inside the database server process. We are currently testing the prototype with two different scientific data sets: The Indra cosmological simulation will use it to store particle and density data from N-body simulations, and the Milky Way Laboratory

SPANG: a SPARQL client supporting generation and reuse of queries for distributed RDF databases.

Science.gov (United States)

Chiba, Hirokazu; Uchiyama, Ikuo

2017-02-08

Toward improved interoperability of distributed biological databases, an increasing number of datasets have been published in the standardized Resource Description Framework (RDF). Although the powerful SPARQL Protocol and RDF Query Language (SPARQL) provides a basis for exploiting RDF databases, writing SPARQL code is burdensome for users including bioinformaticians. Thus, an easy-to-use interface is necessary. We developed SPANG, a SPARQL client that has unique features for querying RDF datasets. SPANG dynamically generates typical SPARQL queries according to specified arguments. It can also call SPARQL template libraries constructed in a local system or published on the Web. Further, it enables combinatorial execution of multiple queries, each with a distinct target database. These features facilitate easy and effective access to RDF datasets and integrative analysis of distributed data. SPANG helps users to exploit RDF datasets by generation and reuse of SPARQL queries through a simple interface. This client will enhance integrative exploitation of biological RDF datasets distributed across the Web. This software package is freely available at http://purl.org/net/spang .

System level traffic shaping in disk servers with heterogeneous protocols

International Nuclear Information System (INIS)

Cano, Eric; Kruse, Daniele Francesco

2014-01-01

Disk access and tape migrations compete for network bandwidth in CASTORs disk servers, over various protocols: RFIO, Xroot, root and GridFTP. As there are a limited number of tape drives, it is important to keep them busy all the time, at their nominal speed. With potentially 100s of user read streams per server, the bandwidth for the tape migrations has to be guaranteed to a controlled level, and not the fair share the system gives by default. Xroot provides a prioritization mechanism, but using it implies moving exclusively to the Xroot protocol, which is not possible in short to mid-term time frame, as users are equally using all protocols. The greatest commonality of all those protocols is not more than the usage of TCP/IP. We investigated the Linux kernel traffic shaper to control TCP/ IP bandwidth. The performance and limitations of the traffic shaper have been understood in test environment, and satisfactory working point has been found for production. Notably, TCP offload engines' negative impact on traffic shaping, and the limitations of the length of the traffic shaping rules were discovered and measured. A suitable working point has been found and the traffic shaping is now successfully deployed in the CASTOR production systems at CERN. This system level approach could be transposed easily to other environments.

Sensitivity Analysis for Multidisciplinary Systems (SAMS)

Science.gov (United States)

2016-12-01

release. Distribution is unlimited. 14 Server and Client Code Server from geometry import Point, Geometry import math import zmq class Server...public release; Distribution is unlimited. DISTRIBUTION STATEMENT A: Approved for public release. Distribution is unlimited. 19 Example Application Boeing...Materials Conference, 2011. Cross, D. M., Local continuum sensitivity method for shape design derivatives using spatial gradient reconstruction. Diss

Tank Information System (tis): a Case Study in Migrating Web Mapping Application from Flex to Dojo for Arcgis Server and then to Open Source

Science.gov (United States)

Pulsani, B. R.

2017-11-01

Tank Information System is a web application which provides comprehensive information about minor irrigation tanks of Telangana State. As part of the program, a web mapping application using Flex and ArcGIS server was developed to make the data available to the public. In course of time as Flex be-came outdated, a migration of the client interface to the latest JavaScript based technologies was carried out. Initially, the Flex based application was migrated to ArcGIS JavaScript API using Dojo Toolkit. Both the client applications used published services from ArcGIS server. To check the migration pattern from proprietary to open source, the JavaScript based ArcGIS application was later migrated to OpenLayers and Dojo Toolkit which used published service from GeoServer. The migration pattern noticed in the study especially emphasizes upon the use of Dojo Toolkit and PostgreSQL database for ArcGIS server so that migration to open source could be performed effortlessly. The current ap-plication provides a case in study which could assist organizations in migrating their proprietary based ArcGIS web applications to open source. Furthermore, the study reveals cost benefits of adopting open source against commercial software's.

A Client/Server Architecture for Supporting Science Data Using EPICS Version 4

Energy Technology Data Exchange (ETDEWEB)

Dalesio, Leo [EPIC Consulting, Jacksonville, FL (United States)

2015-04-21

The Phase 1 grant that serves as a precursor to this proposal, prototyped complex storage techniques for high speed structured data that is being produced in accelerator diagnostics and beam line experiments. It demonstrates the technologies that can be used to archive and retrieve complex data structures and provide the performance required by our new accelerators, instrumentations, and detectors. Phase 2 is proposed to develop a high-performance platform for data acquisition and analysis to provide physicists and operators a better understanding of the beam dynamics. This proposal includes developing a platform for reading 109 MHz data at 10 KHz rates through a multicore front end processor, archiving the data to an archive repository that is then indexed for fast retrieval. The data is then retrieved from this data archive, integrated with the scalar data, to provide data sets to client applications for analysis, use in feedback, and to aid in identifying problem with the instrumentation, plant, beam steering, or model. This development is built on EPICS version 4 , which is being successfully deployed to implement physics applications. Through prior SBIR grants, EPICS version 4 has a solid communication protocol for middle layer services (PVAccess), structured data representation and methods for efficient transportation and access (PVData), an operational hierarchical record environment (JAVA IOC), and prototypes for standard structured data (Normative Types). This work was further developed through project funding to successfully deploy the first service based physics application environment with demonstrated services that provide arbitrary object views, save sets, model, lattice, and unit conversion. Thin client physics applications have been developed in Python that implement quad centering, orbit display, bump control, and slow orbit feedback. This service based architecture has provided a very modular and robust environment that enables commissioning teams

On the single-server retrial queue

Directory of Open Access Journals (Sweden)

Djellab Natalia V.

2006-01-01

Full Text Available In this work, we review the stochastic decomposition for the number of customers in M/G/1 retrial queues with reliable server and server subjected to breakdowns which has been the subject of investigation in the literature. Using the decomposition property of M/G/1 retrial queues with breakdowns that holds under exponential assumption for retrial times as an approximation in the non-exponential case, we consider an approximate solution for the steady-state queue size distribution.

AUTHENTICATION ALGORITHM FOR PARTICIPANTS OF INFORMATION INTEROPERABILITY IN PROCESS OF OPERATING SYSTEM REMOTE LOADING ON THIN CLIENT

Directory of Open Access Journals (Sweden)

Y. A. Gatchin

2016-05-01

Full Text Available Subject of Research.This paper presents solution of authentication problem for all components of information interoperabilityin process of operation system network loading on thin client from terminal server. System Definition. In the proposed solution operation system integrity check is made by hardware-software module, including USB-token with protected memory for secure storage of cryptographic keys and loader. The key requirement for the solution is mutual authentication of four participants: terminal server, thin client, token and user. We have created two algorithms for the problem solution. The first of the designed algorithms compares the encrypted one-time password (random number with the reference value stored in the memory of the token and updates this number in case of successful authentication. The second algorithm uses the public and private keys of the token and the server. As a result of cryptographic transformation, participants are authenticated and the secure channel is formed between the token, thin client and terminal server. Main Results. Additional research was carried out to find out if the designed algorithms meet the necessary requirements. Criteria used included applicability in a multi-access terminal system architecture, potential threats evaluation and overall system security. According to analysis results, it is recommended to use the algorithm based on PKI due to its high scalability and usability. High level of data security is proved as a result of asymmetric cryptography application with the guarantee that participants' private keys are never sent in the authentication process. Practical Relevance. The designed PKI-based algorithm allows solving the problem with the use of cryptographic algorithms according to state standard even in its absence on asymmetric cryptography. Thus, it can be applied in the State Information Systems with increased requirements to information security.

On Mx/(G1G2/1/G(BS/Vs vacation queue with two types of general heterogeneous service

Directory of Open Access Journals (Sweden)

Kailash C. Madan

2005-01-01

Full Text Available We analyze a batch arrival queue with a single server providing two kinds of general heterogeneous service. Just before his service starts, a customer may choose one of the services and as soon as a service (of any kind gets completed, the server may take a vacation or may continue staying in the system. The vacation times are assumed to be general and the server vacations are based on Bernoulli schedules under a single vacation policy. We obtain explicit queue size distribution at a random epoch as well as at a departure epoch and also the mean busy period of the server under the steady state. In addition, some important performance measures such as the expected queue size and the expected waiting time of a customer are obtained. Further, some interesting particular cases are also discussed.

PlanetServer: Innovative approaches for the online analysis of hyperspectral satellite data from Mars

Science.gov (United States)

Oosthoek, J. H. P.; Flahaut, J.; Rossi, A. P.; Baumann, P.; Misev, D.; Campalani, P.; Unnithan, V.

2014-06-01

PlanetServer is a WebGIS system, currently under development, enabling the online analysis of Compact Reconnaissance Imaging Spectrometer (CRISM) hyperspectral data from Mars. It is part of the EarthServer project which builds infrastructure for online access and analysis of huge Earth Science datasets. Core functionality consists of the rasdaman Array Database Management System (DBMS) for storage, and the Open Geospatial Consortium (OGC) Web Coverage Processing Service (WCPS) for data querying. Various WCPS queries have been designed to access spatial and spectral subsets of the CRISM data. The client WebGIS, consisting mainly of the OpenLayers javascript library, uses these queries to enable online spatial and spectral analysis. Currently the PlanetServer demonstration consists of two CRISM Full Resolution Target (FRT) observations, surrounding the NASA Curiosity rover landing site. A detailed analysis of one of these observations is performed in the Case Study section. The current PlanetServer functionality is described step by step, and is tested by focusing on detecting mineralogical evidence described in earlier Gale crater studies. Both the PlanetServer methodology and its possible use for mineralogical studies will be further discussed. Future work includes batch ingestion of CRISM data and further development of the WebGIS and analysis tools.

Design and implementation of streaming media server cluster based on FFMpeg.

Science.gov (United States)

Zhao, Hong; Zhou, Chun-long; Jin, Bao-zhao

2015-01-01

Poor performance and network congestion are commonly observed in the streaming media single server system. This paper proposes a scheme to construct a streaming media server cluster system based on FFMpeg. In this scheme, different users are distributed to different servers according to their locations and the balance among servers is maintained by the dynamic load-balancing algorithm based on active feedback. Furthermore, a service redirection algorithm is proposed to improve the transmission efficiency of streaming media data. The experiment results show that the server cluster system has significantly alleviated the network congestion and improved the performance in comparison with the single server system.

Design and Implementation of Streaming Media Server Cluster Based on FFMpeg

Science.gov (United States)

Zhao, Hong; Zhou, Chun-long; Jin, Bao-zhao

2015-01-01

Poor performance and network congestion are commonly observed in the streaming media single server system. This paper proposes a scheme to construct a streaming media server cluster system based on FFMpeg. In this scheme, different users are distributed to different servers according to their locations and the balance among servers is maintained by the dynamic load-balancing algorithm based on active feedback. Furthermore, a service redirection algorithm is proposed to improve the transmission efficiency of streaming media data. The experiment results show that the server cluster system has significantly alleviated the network congestion and improved the performance in comparison with the single server system. PMID:25734187

EarthServer: Cross-Disciplinary Earth Science Through Data Cube Analytics

Science.gov (United States)

Baumann, P.; Rossi, A. P.

2016-12-01

The unprecedented increase of imagery, in-situ measurements, and simulation data produced by Earth (and Planetary) Science observations missions bears a rich, yet not leveraged potential for getting insights from integrating such diverse datasets and transform scientific questions into actual queries to data, formulated in a standardized way.The intercontinental EarthServer [1] initiative is demonstrating new directions for flexible, scalable Earth Science services based on innovative NoSQL technology. Researchers from Europe, the US and Australia have teamed up to rigorously implement the concept of the datacube. Such a datacube may have spatial and temporal dimensions (such as a satellite image time series) and may unite an unlimited number of scenes. Independently from whatever efficient data structuring a server network may perform internally, users (scientist, planners, decision makers) will always see just a few datacubes they can slice and dice.EarthServer has established client [2] and server technology for such spatio-temporal datacubes. The underlying scalable array engine, rasdaman [3,4], enables direct interaction, including 3-D visualization, common EO data processing, and general analytics. Services exclusively rely on the open OGC "Big Geo Data" standards suite, the Web Coverage Service (WCS). Conversely, EarthServer has shaped and advanced WCS based on the experience gained. The first phase of EarthServer has advanced scalable array database technology into 150+ TB services. Currently, Petabyte datacubes are being built for ad-hoc and cross-disciplinary querying, e.g. using climate, Earth observation and ocean data.We will present the EarthServer approach, its impact on OGC / ISO / INSPIRE standardization, and its platform technology, rasdaman.References: [1] Baumann, et al. (2015) DOI: 10.1080/17538947.2014.1003106 [2] Hogan, P., (2011) NASA World Wind, Proceedings of the 2nd International Conference on Computing for Geospatial Research

Leveraging the Cloud for Integrated Network Experimentation

Science.gov (United States)

2014-03-01

kernel settings, or any of the low-level subcomponents. 3. Scalable Solutions: Businesses can build scalable solutions for their clients , ranging from...values. These values 13 can assume several distributions that include normal, Pareto , uniform, exponential and Poisson, among others [21]. Additionally, D...communication, the web client establishes a connection to the server before traffic begins to flow. Web servers do not initiate connections to clients in

Design of SIP transformation server for efficient media negotiation

Science.gov (United States)

Pack, Sangheon; Paik, Eun Kyoung; Choi, Yanghee

2001-07-01

Voice over IP (VoIP) is one of the advanced services supported by the next generation mobile communication. VoIP should support various media formats and terminals existing together. This heterogeneous environment may prevent diverse users from establishing VoIP sessions among them. To solve the problem an efficient media negotiation mechanism is required. In this paper, we propose the efficient media negotiation architecture using the transformation server and the Intelligent Location Server (ILS). The transformation server is an extended Session Initiation Protocol (SIP) proxy server. It can modify an unacceptable session INVITE message into an acceptable one using the ILS. The ILS is a directory server based on the Lightweight Directory Access Protocol (LDAP) that keeps userí*s location information and available media information. The proposed architecture can eliminate an unnecessary response and re-INVITE messages of the standard SIP architecture. It takes only 1.5 round trip times to negotiate two different media types while the standard media negotiation mechanism takes 2.5 round trip times. The extra processing time in message handling is negligible in comparison to the reduced round trip time. The experimental results show that the session setup time in the proposed architecture is less than the setup time in the standard SIP. These results verify that the proposed media negotiation mechanism is more efficient in solving diversity problems.

Implementing bioinformatic workflows within the bioextract server

Science.gov (United States)

Computational workflows in bioinformatics are becoming increasingly important in the achievement of scientific advances. These workflows typically require the integrated use of multiple, distributed data sources and analytic tools. The BioExtract Server (http://bioextract.org) is a distributed servi...

Enc-DNS-HTTP: Utilising DNS Infrastructure to Secure Web Browsing

Directory of Open Access Journals (Sweden)

Mohammed Abdulridha Hussain

2017-01-01

Full Text Available Online information security is a major concern for both users and companies, since data transferred via the Internet is becoming increasingly sensitive. The World Wide Web uses Hypertext Transfer Protocol (HTTP to transfer information and Secure Sockets Layer (SSL to secure the connection between clients and servers. However, Hypertext Transfer Protocol Secure (HTTPS is vulnerable to attacks that threaten the privacy of information sent between clients and servers. In this paper, we propose Enc-DNS-HTTP for securing client requests, protecting server responses, and withstanding HTTPS attacks. Enc-DNS-HTTP is based on the distribution of a web server public key, which is transferred via a secure communication between client and a Domain Name System (DNS server. This key is used to encrypt client-server communication. The scheme is implemented in the C programming language and tested on a Linux platform. In comparison with Apache HTTPS, this scheme is shown to have more effective resistance to attacks and improved performance since it does not involve a high number of time-consuming operations.

Mobility, Context and Cloud – Exploring Integration Issues in a Meeting Room Scenario

Directory of Open Access Journals (Sweden)

Tor-Morten Grønli

2012-04-01

Full Text Available In this paper we pursue the context-aware paradigm in a distributed mobile environment. Context-awareness plays a significant role in the domain of implicit human computer interaction and we present an intelligent context-aware meeting room application. The distributed mobile application consists of multiple mobile operating system clients, a Google Android based presenter that, through proximity technology, communicates with a server in the meeting room, and a Google Cloud backend server. Over 40 users have evaluated the application. Results show that the context aware meeting room was well received by users who displayed a strong positive bias towards cloud integration and, in particular, automatic meeting-note push. We conclude that our context-aware meeting assistant can provide valuable assistance to end users and that there is promise for such use of heterogeneous mobile context-aware platforms.

Cellular- and micro-dosimetry of heterogeneously distributed tritium.

Science.gov (United States)

Chao, Tsi-Chian; Wang, Chun-Ching; Li, Junli; Li, Chunyan; Tung, Chuan-Jong

2012-01-01

The assessment of radiotoxicity for heterogeneously distributed tritium should be based on the subcellular dose and relative biological effectiveness (RBE) for cell nucleus. In the present work, geometry-dependent absorbed dose and RBE were calculated using Monte Carlo codes for tritium in the cell, cell surface, cytoplasm, or cell nucleus. Penelope (PENetration and Energy LOss of Positrins and Electrons) code was used to calculate the geometry-dependent absorbed dose, lineal energy, and electron fluence spectrum. RBE for the intestinal crypt regeneration was calculated using a lineal energy-dependent biological weighting function. RBE for the induction of DNA double strand breaks was estimated using a nucleotide-level map for clustered DNA lesions of the Monte Carlo damage simulation (MCDS) code. For a typical cell of 10 μm radius and 5 μm nuclear radius, tritium in the cell nucleus resulted in much higher RBE-weighted absorbed dose than tritium distributed uniformly. Conversely, tritium distributed on the cell surface led to trivial RBE-weighted absorbed dose due to irradiation geometry and great attenuation of beta particles in the cytoplasm. For tritium uniformly distributed in the cell, the RBE-weighted absorbed dose was larger compared to tritium uniformly distributed in the tissue. Cellular- and micro-dosimetry models were developed for the assessment of heterogeneously distributed tritium.

UNIX secure server : a free, secure, and functional server example

OpenAIRE

Sastre, Hugo

2016-01-01

The purpose of this thesis work was to introduce UNIX server as a personal server but also as a start point for investigation and developing at a professional level. The objective of this thesis was to build a secure server providing not only a FTP server but also an HTTP server and a cloud system for remote backups. OpenBSD was used as the operating system. OpenBSD is a UNIX-like operating system made by hackers for hackers. The difference with other systems that might partially provid...

Technology insertion of a COTS RAID server as an image buffer in the image chain of the Defense Mapping Agency's Digital Production System

Science.gov (United States)

Mehring, James W.; Thomas, Scott D.

1995-11-01

The Data Services Segment of the Defense Mapping Agency's Digital Production System provides a digital archive of imagery source data for use by DMA's cartographic user's. This system was developed in the mid-1980's and is currently undergoing modernization. This paper addresses the modernization of the imagery buffer function that was performed by custom hardware in the baseline system and is being replaced by a RAID Server based on commercial off the shelf (COTS) hardware. The paper briefly describes the baseline DMA image system and the modernization program, that is currently under way. Throughput benchmark measurements were made to make design configuration decisions for a commercial off the shelf (COTS) RAID Server to perform as system image buffer. The test program began with performance measurements of the RAID read and write operations between the RAID arrays and the server CPU for RAID levels 0, 5 and 0+1. Interface throughput measurements were made for the HiPPI interface between the RAID Server and the image archive and processing system as well as the client side interface between a custom interface board that provides the interface between the internal bus of the RAID Server and the Input- Output Processor (IOP) external wideband network currently in place in the DMA system to service client workstations. End to end measurements were taken from the HiPPI interface through the RAID write and read operations to the IOP output interface.

A large channel count multi client data acquisition system for superconducting magnet system of SST-1

International Nuclear Information System (INIS)

Doshi, K.; Pradhan, S.; Masand, H.; Khristi, Y.; Dhongde, J.; Sharma, A.; Parghi, B.; Varmora, P.; Prasad, U.; Patel, D.

2012-01-01

The magnet system of the Steady-state Superconducting Tokamak-1 at the Institute for Plasma Research, Gandhinagar, India, consists of sixteen Toroidal field and nine Poloidal field Superconducting coils together with a pair of resistive PF coils, an air core ohmic transformer and a pair of vertical field coils. These coils are instrumented with various cryogenic grade sensors and voltage taps to monitor its operating status and health during different operational scenarios. A VME based data acquisition system with remote system architecture is implemented for data acquisition and control of the complete magnet operation. Client-Server based architecture is implemented with remote hardware configuration and continuous online/offline monitoring. A JAVA based platform independent client application is developed for data analysis and data plotting. The server has multiple data pipeline architecture to send data to storage database, online plotting application, numerical display screen, and run time calculation. This paper describes software architecture, design and implementation of the data acquisition system. (author)

creation of unificed geoinformation system for monitoring social and economic developments of departamento quindio (colombia) on the basis of the isolated data sources

Science.gov (United States)

Buravlev, V.; Sereshnikov, S. V.; Mayorov, A. A.; Vila, J. J.

At each level of the state and municipal management the information resources which provide the support of acceptance of administrative decisions, usually are performed as a number of polytypic, untied among themselves electronic data sources, such as databases, geoinformation projects, electronic archives of documents, etc. These sources are located in the various organizations, they function in various programs, and are actualized according to various rules. Creation on the basis of such isolated sources of the uniform information systems which provide an opportunity to look through and analyze any information stored in these sources in real time mode, will help to promote an increase in a degree of adequacy of accepted administrative decisions. The Distributed Data Service technology - TrisoftDDS, developed by company Trisoft, Ltd, provides the construction of horizontal territorially distributed heterogeneous information systems (TeRGIS). Technology TrisoftDDS allows the quickly creation and support, easy modification of systems, the data sources for which are already existing information complexes, without any working capacity infringements of the last ones, and provides the remote regulated multi-user access to the different types of data sources by the Internet/Intranet. Relational databases, GIS projects, files of various types (documents MS Office, images, html documents, etc.) can be used as data sources in TeRGIS. TeRGIS is created as Internet/Intranet application representing three-level client-server system. Access to the information in existing data sources is carried out by means of the distributed DDS data service, the nucleus of which is the distributed data service server - the DSServer, settling down on an intermediate level. TrisoftDDS Technology includes the following components: Client DSBrowser (Data Service Browser) - the client application connected through the Internet/intranet to the DSServer and provides both - a choice and viewing of

TANK INFORMATION SYSTEM (TIS: A CASE STUDY IN MIGRATING WEB MAPPING APPLICATION FROM FLEX TO DOJO FOR ARCGIS SERVER AND THEN TO OPEN SOURCE

Directory of Open Access Journals (Sweden)

B. R. Pulsani

2017-11-01

Full Text Available Tank Information System is a web application which provides comprehensive information about minor irrigation tanks of Telangana State. As part of the program, a web mapping application using Flex and ArcGIS server was developed to make the data available to the public. In course of time as Flex be-came outdated, a migration of the client interface to the latest JavaScript based technologies was carried out. Initially, the Flex based application was migrated to ArcGIS JavaScript API using Dojo Toolkit. Both the client applications used published services from ArcGIS server. To check the migration pattern from proprietary to open source, the JavaScript based ArcGIS application was later migrated to OpenLayers and Dojo Toolkit which used published service from GeoServer. The migration pattern noticed in the study especially emphasizes upon the use of Dojo Toolkit and PostgreSQL database for ArcGIS server so that migration to open source could be performed effortlessly. The current ap-plication provides a case in study which could assist organizations in migrating their proprietary based ArcGIS web applications to open source. Furthermore, the study reveals cost benefits of adopting open source against commercial software's.

Computação de objetos distribuídos na era da internet

Directory of Open Access Journals (Sweden)

Désiré Nguessan

2003-01-01

Full Text Available In this paper, we discuss recent trends in distributed objects and the Internet computing technologies. Both technologies converge to create a paradigm for distributed computing. We provide an overview of CORBA (Common Object Request Broker Architecture, emphasizing its open architecture for distributed application based on distributed objects and the IIOP (Internet Inter-ORB Protocol that improve the integration of the applications in heterogeneous environments. The CORBA protocol is emerging as the business application messaging standard for the Internet and deserves attention from Information Technologies (IT organizations. We conclude that CORBA, together with the Internet, constitute a perfect symbiotic relationship to build, maintain and extend client/server applications with critical mission.

Engineering the CernVM-Filesystem as a High Bandwidth Distributed Filesystem for Auxiliary Physics Data

Energy Technology Data Exchange (ETDEWEB)

Dykstra, D. [Fermilab; Bockelman, B. [Nebraska U.; Blomer, J. [CERN; Herner, K. [Fermilab; Levshina, T. [Fermilab; Slyz, M. [Fermilab

2015-12-23

A common use pattern in the computing models of particle physics experiments is running many distributed applications that read from a shared set of data files. We refer to this data is auxiliary data, to distinguish it from (a) event data from the detector (which tends to be different for every job), and (b) conditions data about the detector (which tends to be the same for each job in a batch of jobs). Relatively speaking, conditions data also tends to be relatively small per job where both event data and auxiliary data are larger per job. Unlike event data, auxiliary data comes from a limited working set of shared files. Since there is spatial locality of the auxiliary data access, the use case appears to be identical to that of the CernVM- Filesystem (CVMFS). However, we show that distributing auxiliary data through CVMFS causes the existing CVMFS infrastructure to perform poorly. We utilize a CVMFS client feature called 'alien cache' to cache data on existing local high-bandwidth data servers that were engineered for storing event data. This cache is shared between the worker nodes at a site and replaces caching CVMFS files on both the worker node local disks and on the site's local squids. We have tested this alien cache with the dCache NFSv4.1 interface, Lustre, and the Hadoop Distributed File System (HDFS) FUSE interface, and measured performance. In addition, we use high-bandwidth data servers at central sites to perform the CVMFS Stratum 1 function instead of the low-bandwidth web servers deployed for the CVMFS software distribution function. We have tested this using the dCache HTTP interface. As a result, we have a design for an end-to-end high-bandwidth distributed caching read-only filesystem, using existing client software already widely deployed to grid worker nodes and existing file servers already widely installed at grid sites. Files are published in a central place and are soon available on demand throughout the grid and cached

Engineering the CernVM-Filesystem as a High Bandwidth Distributed Filesystem for Auxiliary Physics Data

Science.gov (United States)

Dykstra, D.; Bockelman, B.; Blomer, J.; Herner, K.; Levshina, T.; Slyz, M.

2015-12-01

A common use pattern in the computing models of particle physics experiments is running many distributed applications that read from a shared set of data files. We refer to this data is auxiliary data, to distinguish it from (a) event data from the detector (which tends to be different for every job), and (b) conditions data about the detector (which tends to be the same for each job in a batch of jobs). Relatively speaking, conditions data also tends to be relatively small per job where both event data and auxiliary data are larger per job. Unlike event data, auxiliary data comes from a limited working set of shared files. Since there is spatial locality of the auxiliary data access, the use case appears to be identical to that of the CernVM- Filesystem (CVMFS). However, we show that distributing auxiliary data through CVMFS causes the existing CVMFS infrastructure to perform poorly. We utilize a CVMFS client feature called "alien cache" to cache data on existing local high-bandwidth data servers that were engineered for storing event data. This cache is shared between the worker nodes at a site and replaces caching CVMFS files on both the worker node local disks and on the site's local squids. We have tested this alien cache with the dCache NFSv4.1 interface, Lustre, and the Hadoop Distributed File System (HDFS) FUSE interface, and measured performance. In addition, we use high-bandwidth data servers at central sites to perform the CVMFS Stratum 1 function instead of the low-bandwidth web servers deployed for the CVMFS software distribution function. We have tested this using the dCache HTTP interface. As a result, we have a design for an end-to-end high-bandwidth distributed caching read-only filesystem, using existing client software already widely deployed to grid worker nodes and existing file servers already widely installed at grid sites. Files are published in a central place and are soon available on demand throughout the grid and cached locally on the

Heterogeneity of D-Serine Distribution in the Human Central Nervous System

Science.gov (United States)

Suzuki, Masataka; Imanishi, Nobuaki; Mita, Masashi; Hamase, Kenji; Aiso, Sadakazu

2017-01-01

D-serine is an endogenous ligand for N-methyl-D-aspartate glutamate receptors. Accumulating evidence including genetic associations of D-serine metabolism with neurological or psychiatric diseases suggest that D-serine is crucial in human neurophysiology. However, distribution and regulation of D-serine in humans are not well understood. Here, we found that D-serine is heterogeneously distributed in the human central nervous system (CNS). The cerebrum contains the highest level of D-serine among the areas in the CNS. There is heterogeneity in its distribution in the cerebrum and even within the cerebral neocortex. The neocortical heterogeneity is associated with Brodmann or functional areas but is unrelated to basic patterns of cortical layer structure or regional expressional variation of metabolic enzymes for D-serine. Such D-serine distribution may reflect functional diversity of glutamatergic neurons in the human CNS, which may serve as a basis for clinical and pharmacological studies on D-serine modulation. PMID:28604057

Proposal and Implementation of SSH Client System Using Ajax

Science.gov (United States)

Kosuda, Yusuke; Sasaki, Ryoichi

Technology called Ajax gives web applications the functionality and operability of desktop applications. In this study, we propose and implement a Secure Shell (SSH) client system using Ajax, independent of the OS or Java execution environment. In this system, SSH packets are generated on a web browser by using JavaScript and a web server works as a proxy in communication with an SSH server to realize end-to-end SSH communication. We implemented a prototype program and confirmed by experiment that it runs on several web browsers and mobile phones. This system has enabled secure SSH communication from a PC at an Internet cafe or any mobile phone. By measuring the processing performance, we verified satisfactory performance for emergency use, although the speed was unsatisfactory in some cases with mobile phone. The system proposed in this study will be effective in various fields of E-Business.

Using Servers to Enhance Control System Capability

International Nuclear Information System (INIS)

Bickley, M.; Bowling, B. A.; Bryan, D. A.; Zeijts, J. van; White, K. S.; Witherspoon, S.

1999-01-01

Many traditional control systems include a distributed collection of front end machines to control hardware. Backend tools are used to view, modify, and record the signals generated by these front end machines. Software servers, which are a middleware layer between the front and back ends, can improve a control system in several ways. Servers can enable on-line processing of raw data, and consolidation of functionality. It many cases data retrieved from the front end must be processed in order to convert the raw data into useful information. These calculations are often redundantly performance by different programs, frequently offline. Servers can monitor the raw data and rapidly perform calculations, producing new signals which can be treated like any other control system signal, and can be used by any back end application. Algorithms can be incorporated to actively modify signal values in the control system based upon changes of other signals, essentially producing feedback in a control system. Servers thus increase the flexibility of a control system. Lastly, servers running on inexpensive UNIXworkstations can relay or cache frequently needed information, reducing the load on front end hardware by functioning as concentrators. Rather than many back end tools connecting directly to the front end machines, increasing the work load of these machines, they instead connect to the server. Servers like those discussed above have been used successfully at the Thomas Jefferson National Accelerator Facility to provide functionality such as beam steering, fault monitoring, storage of machine parameters, and on-line data processing. The authors discuss the potential uses of such servers, and share the results of work performed to date

Proving the correctness of client/server software

Indian Academy of Sciences (India)

ness of an OSEKtime (OSE 2001) like distributed real time operating system and all ... kernel but concentrate on the security-sensitive services running on top of it. This multi- ...... in case of a call to a procedure other than MUL send denial. (16).

Development of Client Environments for a Synchronization System based on Events; Desarrollo de Entornos Cliente para un Sistema de Sincronizacion Basado en Eventos

Energy Technology Data Exchange (ETDEWEB)

Pereira, A.; Vega, J.

2005-07-01

The Asynchronous Event Distribution System (AEDS) was built to provides synchronization resources within the TJ-II local area network. It is a software system developed to add soft synchronization capabilities to the TJ-II data acquisition, control and analysis environments Soft synchronization signifies that AEDS is not a realtime system. In fact, AEDS is based on TCP/IP over ETHERNET networks. However, its response time is adequate for practical purposes when synchronization requirements can support some delay between event dispatch and message reception. Event broadcasters (or synchronization servers in AEDS terminology) are Windows computers. Destination computers (or synchronization clients) were also Windows machines in the first version of AEDS. However, this fact imposed a very important limitation on synchronization capabilities. to overcome this situation, synchronization clients for different environments have been added to AEDS: time-sharing operating systems (UNIX and LINUX), real-time operating systems (OS9 and VxWorks) and Java applications. The synchronization primitives that operate in these systems are very different between them and therefore, several approaches were chosen in order to provide the same functionality to the various environments. POSLX thread library with its basic synchronization primitives (mutex and conditions variables) was used to accomplish this task on UNIX/LINUX systems, IPC mechanisms for concurrent processes on OS9 and VxWorks real time operating systems, and synchronized-wait/notify primitives on Java virtual machines. (Author) 11 refs.

CMS distributed analysis infrastructure and operations: experience with the first LHC data

International Nuclear Information System (INIS)

Vaandering, E W

2011-01-01

The CMS distributed analysis infrastructure represents a heterogeneous pool of resources distributed across several continents. The resources are harnessed using glite and glidein-based work load management systems (WMS). We provide the operational experience of the analysis workflows using CRAB-based servers interfaced with the underlying WMS. The automatized interaction of the server with the WMS provides a successful analysis workflow. We present the operational experience as well as methods used in CMS to analyze the LHC data. The interaction with CMS Run-registry for Run and luminosity block selections via CRAB is discussed. The variations of different workflows during the LHC data-taking period and the lessons drawn from this experience are also outlined.

An approach for heterogeneous and loosely coupled geospatial data distributed computing

Science.gov (United States)

Chen, Bin; Huang, Fengru; Fang, Yu; Huang, Zhou; Lin, Hui

2010-07-01

Most GIS (Geographic Information System) applications tend to have heterogeneous and autonomous geospatial information resources, and the availability of these local resources is unpredictable and dynamic under a distributed computing environment. In order to make use of these local resources together to solve larger geospatial information processing problems that are related to an overall situation, in this paper, with the support of peer-to-peer computing technologies, we propose a geospatial data distributed computing mechanism that involves loosely coupled geospatial resource directories and a term named as Equivalent Distributed Program of global geospatial queries to solve geospatial distributed computing problems under heterogeneous GIS environments. First, a geospatial query process schema for distributed computing as well as a method for equivalent transformation from a global geospatial query to distributed local queries at SQL (Structured Query Language) level to solve the coordinating problem among heterogeneous resources are presented. Second, peer-to-peer technologies are used to maintain a loosely coupled network environment that consists of autonomous geospatial information resources, thus to achieve decentralized and consistent synchronization among global geospatial resource directories, and to carry out distributed transaction management of local queries. Finally, based on the developed prototype system, example applications of simple and complex geospatial data distributed queries are presented to illustrate the procedure of global geospatial information processing.

Content-Agnostic Malware Detection in Heterogeneous Malicious Distribution Graph

KAUST Repository

Alabdulmohsin, Ibrahim

2016-10-26

Malware detection has been widely studied by analysing either file dropping relationships or characteristics of the file distribution network. This paper, for the first time, studies a global heterogeneous malware delivery graph fusing file dropping relationship and the topology of the file distribution network. The integration offers a unique ability of structuring the end-to-end distribution relationship. However, it brings large heterogeneous graphs to analysis. In our study, an average daily generated graph has more than 4 million edges and 2.7 million nodes that differ in type, such as IPs, URLs, and files. We propose a novel Bayesian label propagation model to unify the multi-source information, including content-agnostic features of different node types and topological information of the heterogeneous network. Our approach does not need to examine the source codes nor inspect the dynamic behaviours of a binary. Instead, it estimates the maliciousness of a given file through a semi-supervised label propagation procedure, which has a linear time complexity w.r.t. the number of nodes and edges. The evaluation on 567 million real-world download events validates that our proposed approach efficiently detects malware with a high accuracy. © 2016 Copyright held by the owner/author(s).

Obtaining contaminant arrival distributions for steady flow in heterogeneous systems

International Nuclear Information System (INIS)

Anon.

1977-01-01

The versatility of the new contaminant arrival distributions for determining environmental consequences of subsurface pollution problems is demonstrated through application to a field example involving land drainage in heterogeneous porous materials. Though the four phases of the hydrologic evaluations are complicated because of the material heterogeneity encountered in the field problem, the arrival distributions still effectively summarize the minimal amount of data required to determine the environmental implications. These arrival distributions yield a single graph or tabular set of data giving the consequences of the subsurface pollution problems. Accordingly, public control authorities would be well advised to request that the results of subsurface pollution investigations be provided in the form of arrival distributions and the resulting simpler summary curve or tabulation. Such an objective is most easily accomplished through compliance with the requirements for assuring a complete subsurface evaluation

A MODEL OF HETEROGENEOUS DISTRIBUTED SYSTEM FOR FOREIGN EXCHANGE PORTFOLIO ANALYSIS

Directory of Open Access Journals (Sweden)

Dragutin Kermek

2006-06-01

Full Text Available The paper investigates the design of heterogeneous distributed system for foreign exchange portfolio analysis. The proposed model includes few separated and dislocated but connected parts through distributed mechanisms. Making system distributed brings new perspectives to performance busting where software based load balancer gets very important role. Desired system should spread over multiple, heterogeneous platforms in order to fulfil open platform goal. Building such a model incorporates different patterns from GOF design patterns, business patterns, J2EE patterns, integration patterns, enterprise patterns, distributed design patterns to Web services patterns. The authors try to find as much as possible appropriate patterns for planned tasks in order to capture best modelling and programming practices.

Two Stage Secure Dynamic Load Balancing Architecture for SIP Server Clusters

Directory of Open Access Journals (Sweden)

G. Vennila

2014-08-01

Full Text Available Session Initiation Protocol (SIP is a signaling protocol emerged with an aim to enhance the IP network capabilities in terms of complex service provision. SIP server scalability with load balancing has a greater concern due to the dramatic increase in SIP service demand. Load balancing of session method (request/response and security measures optimizes the SIP server to regulate of network traffic in Voice over Internet Protocol (VoIP. Establishing a honeywall prior to the load balancer significantly reduces SIP traffic and drops inbound malicious load. In this paper, we propose Active Least Call in SIP Server (ALC_Server algorithm fulfills objectives like congestion avoidance, improved response times, throughput, resource utilization, reducing server faults, scalability and protection of SIP call from DoS attacks. From the test bed, the proposed two-tier architecture demonstrates that the ALC_Server method dynamically controls the overload and provides robust security, uniform load distribution for SIP servers.

A Web Services based system for the distribution of live information at the FTU fusion experiment

International Nuclear Information System (INIS)

Boncagni, L.; Centioli, C.; Lattanzio, L.; Panella, M.; Torelli, C.; Zaccarian, L.

2009-01-01

In this paper we describe LiveMonitor, an integrated system realized for the distribution of information in fusion environments. The software tool is based on a client-server approach, where the server side consists of a set of Web Services that collect data from a variety of data sources. LiveMonitor has been successfully used at FTU, replacing and enhancing part of the core of the current message broadcasting system. The tool integrates all the information needed by the control room personnel during the experiments, namely the shot sequence status coming from the FTU Control System, videos of the plasma discharge from the FTU ports cameras, and fresh data from the databases. From the hardware point of view, the new system is made of a Linux node running the Web Services, while clients running on other machines can display information on large (46 '' ) LCD monitors. The tool has been tested during FTU experiments and can be further expanded to match the needs of the control room personnel and experimental physicists.

MetaRanker 2.0: a web server for prioritization of genetic variation data

DEFF Research Database (Denmark)

Pers, Tune Hannes; Dworzynski, Piotr; Thomas, Cecilia Engel

2013-01-01

MetaRanker 2.0 is a web server for prioritization of common and rare frequency genetic variation data. Based on heterogeneous data sets including genetic association data, protein–protein interactions, large-scale text-mining data, copy number variation data and gene expression experiments, Meta...

Cloud-Based Parameter-Driven Statistical Services and Resource Allocation in a Heterogeneous Platform on Enterprise Environment

Directory of Open Access Journals (Sweden)

Sungju Lee

2016-09-01

Full Text Available A fundamental key for enterprise users is a cloud-based parameter-driven statistical service and it has become a substantial impact on companies worldwide. In this paper, we demonstrate the statistical analysis for some certain criteria that are related to data and applied to the cloud server for a comparison of results. In addition, we present a statistical analysis and cloud-based resource allocation method for a heterogeneous platform environment by performing a data and information analysis with consideration of the application workload and the server capacity, and subsequently propose a service prediction model using a polynomial regression model. In particular, our aim is to provide stable service in a given large-scale enterprise cloud computing environment. The virtual machines (VMs for cloud-based services are assigned to each server with a special methodology to satisfy the uniform utilization distribution model. It is also implemented between users and the platform, which is a main idea of our cloud computing system. Based on the experimental results, we confirm that our prediction model can provide sufficient resources for statistical services to large-scale users while satisfying the uniform utilization distribution.

GeoServer cookbook

CERN Document Server

Iacovella, Stefano

2014-01-01

This book is ideal for GIS experts, developers, and system administrators who have had a first glance at GeoServer and who are eager to explore all its features in order to configure professional map servers. Basic knowledge of GIS and GeoServer is required.

Heterogeneous ice slurry flow and concentration distribution in horizontal pipes

International Nuclear Information System (INIS)

Wang, Jihong; Zhang, Tengfei; Wang, Shugang

2013-01-01

Highlights: • A Mixture CFD model is applied to describe heterogeneous ice slurry flow. • The ice slurry rheological behavior is considered piecewise. • The coupled flow and concentration profiles in heterogeneous slurry flow is acquired. • The current numerical model achieves good balance between precision and universality. -- Abstract: Ice slurry is an energy-intensive solid–liquid mixture fluid which may play an important role in various cooling purposes. Knowing detailed flow information is important from the system design point of view. However, the heterogeneous ice slurry flow makes it difficult to be quantified due to the complex two phase flow characteristic. The present study applies a Mixture computational fluid dynamics (CFD) model based on different rheological behavior to characterize the heterogeneous ice slurry flow. The Mixture CFD model was firstly validated by three different experiments. Then the validated Mixture CFD model was applied to solve the ice slurry isothermal flow by considering the rheological behavior piecewise. Finally, the numerical solutions have displayed the coupled flow information, such as slurry velocity, ice particle concentration and pressure drop distribution. The results show that, the ice slurry flow distribution will appear varying degree of asymmetry under different operating conditions. The rheological behavior will be affected by the asymmetric flow distributions. When mean flow velocity is high, Thomas equation can be appropriate for describing ice slurry viscosity. While with the decreasing of mean flow velocity, the ice slurry behaves Bingham rheology. As compared with experimental pressure drop results, the relative errors of numerical computation are almost within ±15%. The Mixture CFD model is validated to be an effective model for describing heterogeneous ice slurry flow and could supply plentiful flow information

The optimal control in batch arrival queue with server vacations, startup and breakdowns

Directory of Open Access Journals (Sweden)

Ke Jau-Chuan

2004-01-01

Full Text Available This paper studies the N policy M[x]/G/1 queue with server vacations; startup and breakdowns, where arrivals form a compound Poisson process and service times are generally distributed. The server is turned off and takes a vacation whenever the system is empty. If the number of customers waiting in the system at the instant of a vacation completion is less than N, the server will take another vacation. If the server returns from a vacation and finds at least N customers in the system, he is immediately turned on and requires a startup time before providing the service until the system is empty again. It is assumed that the server breaks down according to a Poisson process whose repair time has a general distribution. The system characteristics of such a model are analyzed and the total expected cost function per unit time is developed to determine the optimal threshold of N at a minimum cost.

Upgrading a TCABR data analysis and acquisition system for remote participation using Java, XML, RCP and modern client/server communication/authentication

International Nuclear Information System (INIS)

Sa, W.P. de

2010-01-01

The TCABR data analysis and acquisition system has been upgraded to support a joint research programme using remote participation technologies. The architecture of the new system uses Java language as programming environment. Since application parameters and hardware in a joint experiment are complex with a large variability of components, requirements and specification solutions need to be flexible and modular, independent from operating system and computer architecture. To describe and organize the information on all the components and the connections among them, systems are developed using the eXtensible Markup Language (XML) technology. The communication between clients and servers uses remote procedure call (RPC) based on the XML (RPC-XML technology). The integration among Java language, XML and RPC-XML technologies allows to develop easily a standard data and communication access layer between users and laboratories using common software libraries and Web application. The libraries allow data retrieval using the same methods for all user laboratories in the joint collaboration, and the Web application allows a simple graphical user interface (GUI) access. The TCABR tokamak team in collaboration with the IPFN (Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa) is implementing this remote participation technologies. The first version was tested at the Joint Experiment on TCABR (TCABRJE), a Host Laboratory Experiment, organized in cooperation with the IAEA (International Atomic Energy Agency) in the framework of the IAEA Coordinated Research Project (CRP) on 'Joint Research Using Small Tokamaks'.

Upgrading a TCABR data analysis and acquisition system for remote participation using Java, XML, RCP and modern client/server communication/authentication

Energy Technology Data Exchange (ETDEWEB)

Sa, W.P. de, E-mail: pires@if.usp.b [Instituto de Fisica, Universidade de Sao Paulo, Rua do Matao, Travessa R, 187 CEP 05508-090 Cidade Universitaria, Sao Paulo (Brazil)

2010-07-15

The TCABR data analysis and acquisition system has been upgraded to support a joint research programme using remote participation technologies. The architecture of the new system uses Java language as programming environment. Since application parameters and hardware in a joint experiment are complex with a large variability of components, requirements and specification solutions need to be flexible and modular, independent from operating system and computer architecture. To describe and organize the information on all the components and the connections among them, systems are developed using the eXtensible Markup Language (XML) technology. The communication between clients and servers uses remote procedure call (RPC) based on the XML (RPC-XML technology). The integration among Java language, XML and RPC-XML technologies allows to develop easily a standard data and communication access layer between users and laboratories using common software libraries and Web application. The libraries allow data retrieval using the same methods for all user laboratories in the joint collaboration, and the Web application allows a simple graphical user interface (GUI) access. The TCABR tokamak team in collaboration with the IPFN (Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa) is implementing this remote participation technologies. The first version was tested at the Joint Experiment on TCABR (TCABRJE), a Host Laboratory Experiment, organized in cooperation with the IAEA (International Atomic Energy Agency) in the framework of the IAEA Coordinated Research Project (CRP) on 'Joint Research Using Small Tokamaks'.

IMIS desktop & smartphone software solutions for monitoring spacecrafts' payload from anywhere

Science.gov (United States)

Baroukh, J.; Queyrut, O.; Airaud, J.

In the past years, the demand for satellite remote operations has increased guided by on one hand, the will to reduce operations cost (on-call operators out of business hours), and on the other hand, the development of cooperation space missions resulting in a world wide distribution of engineers and science team members. Only a few off-the-shelf solutions exist to fulfill the need of remote payload monitoring, and they mainly use proprietary devices. The recent advent of mobile technologies (laptops, smartphones and tablets) as well as the worldwide deployment of broadband networks (3G, Wi-Fi hotspots), has opened up a technical window that brings new options. As part of the Mars Science Laboratory (MSL) mission, the Centre National D'Etudes Spatiales (CNES, the French space agency) has developed a new software solution for monitoring spacecraft payloads. The Instrument Monitoring Interactive Software (IMIS) offers state-of-the-art operational features for payload monitoring, and can be accessed remotely. It was conceived as a generic tool that can be used for heterogeneous payloads and missions. IMIS was designed as a classical client/server architecture. The server is hosted at CNES and acts as a data provider while two different kinds of clients are available depending on the level of mobility required. The first one is a rich client application, built on Eclipse framework, which can be installed on usual operating systems and communicates with the server through the Internet. The second one is a smartphone application for any Android platform, connected to the server thanks to the mobile broadband network or a Wi-Fi connection. This second client is mainly devoted to on-call operations and thus only contains a subset of the IMIS functionalities. This paper describes the operational context, including security aspects, that led IMIS development, presents the selected software architecture and details the various features of both clients: the desktop and the sm

NSLS-II High Level Application Infrastructure And Client API Design

International Nuclear Information System (INIS)

Shen, G.; Yang, L.; Shroff, K.

2011-01-01

The beam commissioning software framework of NSLS-II project adopts a client/server based architecture to replace the more traditional monolithic high level application approach. It is an open structure platform, and we try to provide a narrow API set for client application. With this narrow API, existing applications developed in different language under different architecture could be ported to our platform with small modification. This paper describes system infrastructure design, client API and system integration, and latest progress. As a new 3rd generation synchrotron light source with ultra low emittance, there are new requirements and challenges to control and manipulate the beam. A use case study and a theoretical analysis have been performed to clarify requirements and challenges to the high level applications (HLA) software environment. To satisfy those requirements and challenges, adequate system architecture of the software framework is critical for beam commissioning, study and operation. The existing traditional approaches are self-consistent, and monolithic. Some of them have adopted a concept of middle layer to separate low level hardware processing from numerical algorithm computing, physics modelling, data manipulating, plotting, and error handling. However, none of the existing approaches can satisfy the requirement. A new design has been proposed by introducing service oriented architecture technology. The HLA is combination of tools for accelerator physicists and operators, which is same as traditional approach. In NSLS-II, they include monitoring applications and control routines. Scripting environment is very important for the later part of HLA and both parts are designed based on a common set of APIs. Physicists and operators are users of these APIs, while control system engineers and a few accelerator physicists are the developers of these APIs. With our Client/Server mode based approach, we leave how to retrieve information to the

Electrical resistivity sounding to study water content distribution in heterogeneous soils

Science.gov (United States)

Electrical resistivity (ER) sounding is increasingly being used as non-invasive technique to reveal and map soil heterogeneity. The objective of this work was to assess ER sounding applicability to study soil water distribution in spatially heterogeneous soils. The 30x30-m study plot was located at ...

ADAPTIVE DISTRIBUTION OF A SWARM OF HETEROGENEOUS ROBOTS

Directory of Open Access Journals (Sweden)

Amanda Prorok

2016-02-01

Full Text Available We present a method that distributes a swarm of heterogeneous robots among a set of tasks that require specialized capabilities in order to be completed. We model the system of heterogeneous robots as a community of species, where each species (robot type is defined by the traits (capabilities that it owns. Our method is based on a continuous abstraction of the swarm at a macroscopic level as we model robots switching between tasks. We formulate an optimization problem that produces an optimal set of transition rates for each species, so that the desired trait distribution is reached as quickly as possible. Since our method is based on the derivation of an analytical gradient, it is very efficient with respect to state-of-the-art methods. Building on this result, we propose a real-time optimization method that enables an online adaptation of transition rates. Our approach is well-suited for real-time applications that rely on online redistribution of large-scale robotic systems.

Generative Adversarial Networks Based Heterogeneous Data Integration and Its Application for Intelligent Power Distribution and Utilization

Directory of Open Access Journals (Sweden)

Yuanpeng Tan

2018-01-01

Full Text Available Heterogeneous characteristics of a big data system for intelligent power distribution and utilization have already become more and more prominent, which brings new challenges for the traditional data analysis technologies and restricts the comprehensive management of distribution network assets. In order to solve the problem that heterogeneous data resources of power distribution systems are difficult to be effectively utilized, a novel generative adversarial networks (GANs based heterogeneous data integration method for intelligent power distribution and utilization is proposed. In the proposed method, GANs theory is introduced to expand the distribution of completed data samples. Then, a so-called peak clustering algorithm is proposed to realize the finite open coverage of the expanded sample space, and repair those incomplete samples to eliminate the heterogeneous characteristics. Finally, in order to realize the integration of the heterogeneous data for intelligent power distribution and utilization, the well-trained discriminator model of GANs is employed to check the restored data samples. The simulation experiments verified the validity and stability of the proposed heterogeneous data integration method, which provides a novel perspective for the further data quality management of power distribution systems.

Heterogeneous Data Fusion Method to Estimate Travel Time Distributions in Congested Road Networks

OpenAIRE

Chaoyang Shi; Bi Yu Chen; William H. K. Lam; Qingquan Li

2017-01-01

Travel times in congested urban road networks are highly stochastic. Provision of travel time distribution information, including both mean and variance, can be very useful for travelers to make reliable path choice decisions to ensure higher probability of on-time arrival. To this end, a heterogeneous data fusion method is proposed to estimate travel time distributions by fusing heterogeneous data from point and interval detectors. In the proposed method, link travel time distributions are f...

Observed and unobserved heterogeneity in stochastic frontier models: An application to the electricity distribution industry

International Nuclear Information System (INIS)

Kopsakangas-Savolainen, Maria; Svento, Rauli

2011-01-01

In this study we combine different possibilities to model firm level heterogeneity in stochastic frontier analysis. We show that both observed and unobserved heterogeneities cause serious biases in inefficiency results. Modelling observed and unobserved heterogeneities treat individual firms in different ways and even though the expected mean inefficiency scores in both cases diminish the firm level efficiency rank orders turn out to be very different. The best fit with the data is obtained by modelling unobserved heterogeneity through randomizing frontier parameters and at the same time explicitly modelling the observed heterogeneity into the inefficiency distribution. These results are obtained by using data from Finnish electricity distribution utilities and the results are relevant in relation to electricity distribution pricing and regulation. -- Research Highlights: → We show that both observed and unobserved heterogeneities of firms cause biases in inefficiency results. → Different ways of accounting firm level heterogeneity end up with very different rank orders of firms. → The model which combines the characteristics of unobserved and observed heterogeneity fits the data best.

Distributed chemical computing using ChemStar: an open source java remote method invocation architecture applied to large scale molecular data from PubChem.

Science.gov (United States)

Karthikeyan, M; Krishnan, S; Pandey, Anil Kumar; Bender, Andreas; Tropsha, Alexander

2008-04-01

We present the application of a Java remote method invocation (RMI) based open source architecture to distributed chemical computing. This architecture was previously employed for distributed data harvesting of chemical information from the Internet via the Google application programming interface (API; ChemXtreme). Due to its open source character and its flexibility, the underlying server/client framework can be quickly adopted to virtually every computational task that can be parallelized. Here, we present the server/client communication framework as well as an application to distributed computing of chemical properties on a large scale (currently the size of PubChem; about 18 million compounds), using both the Marvin toolkit as well as the open source JOELib package. As an application, for this set of compounds, the agreement of log P and TPSA between the packages was compared. Outliers were found to be mostly non-druglike compounds and differences could usually be explained by differences in the underlying algorithms. ChemStar is the first open source distributed chemical computing environment built on Java RMI, which is also easily adaptable to user demands due to its "plug-in architecture". The complete source codes as well as calculated properties along with links to PubChem resources are available on the Internet via a graphical user interface at http://moltable.ncl.res.in/chemstar/.

Secure Distributed Databases Using Cryptography

Directory of Open Access Journals (Sweden)

Ion IVAN

2006-01-01

Full Text Available The computational encryption is used intensively by different databases management systems for ensuring privacy and integrity of information that are physically stored in files. Also, the information is sent over network and is replicated on different distributed systems. It is proved that a satisfying level of security is achieved if the rows and columns of tables are encrypted independently of table or computer that sustains the data. Also, it is very important that the SQL - Structured Query Language query requests and responses to be encrypted over the network connection between the client and databases server. All this techniques and methods must be implemented by the databases administrators, designer and developers in a consistent security policy.

User rights management of the CSNS control system client

International Nuclear Information System (INIS)

Zhang Zhuoyu; Liu Minqian; Chu Yuanping; Zhuang Jian; Hu Lei; Jin Dapeng

2012-01-01

The China Spallation Neutron Source (CSNS) will become the first pulsed spallation neutron source owned by China, CSS (Control System Studio), used as the the target station and spectrometer control system client, is mainly responsible for equipment controlling and parameter monitoring. In order to ensure the safety of the control system, the advanced GUI and important operating parameters must be restricted to ordinary users, only senior experts have the rights to view and modify them, so we must divide CSS users into different groups and give different rights to different groups. Based on user roles, CSS can implicit workbench contents and widgets, to ensure that users can seamlessly log into different clients. This article mainly talk about the JAAS authentication and authorization services in CSS, and deploy user information and master-slave synchronization information on the LDAP server, and use the Eclipse activity extension points to accomplish GUI explicit-implicit control according to the logged in user. (authors)

Beginning SQL Server Modeling Model-driven Application Development in SQL Server

CERN Document Server

Weller, Bart

2010-01-01

Get ready for model-driven application development with SQL Server Modeling! This book covers Microsoft's SQL Server Modeling (formerly known under the code name "Oslo") in detail and contains the information you need to be successful with designing and implementing workflow modeling. Beginning SQL Server Modeling will help you gain a comprehensive understanding of how to apply DSLs and other modeling components in the development of SQL Server implementations. Most importantly, after reading the book and working through the examples, you will have considerable experience using SQL M

Anxiety in mammography: mammographers' and clients' perspectives

International Nuclear Information System (INIS)

Galletta, S.; Joel, N.; Maguire, R.; Weaver, K.; Poulos, A.

2003-01-01

The aim of this study was to identify causes of anxiety experienced by mammographers and clients during mammography and strategies to decrease the anxiety generated by the mammographic procedure. Two questionnaires were distributed: one to mammographers in public and private centres within NSW, the other to women (clients) who have experienced mammography. Mammographers' and clients' rankings of causes of clients' anxiety demonstrated many similarities indicating the mammographers' acknowledgement of factors contributing to client anxiety. Thematic analysis provided important qualitative data concerning anxiety experienced by both mammographers and clients and the influence of mammographer and client behaviour on that anxiety. The results of this study have provided important new knowledge for mammographic practice and mammography education. By understanding the causes of anxiety experienced by clients, mammographers can provide an informed, empathetic approach to the mammographic process. By acknowledging factors which increase their own anxiety mammographers can reduce the impact of this on themselves and on their clients. Copyright (2003) Australian Institute of Radiography

Mastering Lync Server 2010

CERN Document Server

Winters, Nathan

2012-01-01

An in-depth guide on the leading Unified Communications platform Microsoft Lync Server 2010 maximizes communication capabilities in the workplace like no other Unified Communications (UC) solution. Written by experts who know Lync Server inside and out, this comprehensive guide shows you step by step how to administer the newest and most robust version of Lync Server. Along with clear and detailed instructions, learning is aided by exercise problems and real-world examples of established Lync Server environments. You'll gain the skills you need to effectively deploy Lync Server 2010 and be on

Distribution of model-based multipoint heterogeneity lod scores.

Science.gov (United States)

Xing, Chao; Morris, Nathan; Xing, Guan

2010-12-01

The distribution of two-point heterogeneity lod scores (HLOD) has been intensively investigated because the conventional χ(2) approximation to the likelihood ratio test is not directly applicable. However, there was no study investigating th e distribution of the multipoint HLOD despite its wide application. Here we want to point out that, compared with the two-point HLOD, the multipoint HLOD essentially tests for homogeneity given linkage and follows a relatively simple limiting distribution ½χ²₀+ ½χ²₁, which can be obtained by established statistical theory. We further examine the theoretical result by simulation studies. © 2010 Wiley-Liss, Inc.

Effect of heterogeneous microvasculature distribution on drug delivery to solid tumour

International Nuclear Information System (INIS)

Zhan, Wenbo; Xu, Xiao Yun; Gedroyc, Wladyslaw

2014-01-01

Most of the computational models of drug transport in vascular tumours assume a uniform distribution of blood vessels through which anti-cancer drugs are delivered. However, it is well known that solid tumours are characterized by dilated microvasculature with non-uniform diameters and irregular branching patterns. In this study, the effect of heterogeneous vasculature on drug transport and uptake is investigated by means of mathematical modelling of the key physical and biochemical processes in drug delivery. An anatomically realistic tumour model accounting for heterogeneous distribution of blood vessels is reconstructed based on magnetic resonance images of a liver tumour. Numerical simulations are performed for different drug delivery modes, including direct continuous infusion and thermosensitive liposome-mediated delivery, and the anti-cancer effectiveness is evaluated through changes in tumour cell density based on predicted intracellular concentrations. Comparisons are made between regions of different vascular density, and between the two drug delivery modes. Our numerical results show that both extra- and intra-cellular concentrations in the liver tumour are non-uniform owing to the heterogeneous distribution of tumour vasculature. Drugs accumulate faster in well-vascularized regions, where they are also cleared out more quickly, resulting in less effective tumour cell killing in these regions. Compared with direct continuous infusion, the influence of heterogeneous vasculature on anti-cancer effectiveness is more pronounced for thermosensitive liposome-mediated delivery. (paper)

Protect Heterogeneous Environment Distributed Computing from Malicious Code Assignment

Directory of Open Access Journals (Sweden)

V. S. Gorbatov

2011-09-01

Full Text Available The paper describes the practical implementation of the protection system of heterogeneous environment distributed computing from malicious code for the assignment. A choice of technologies, development of data structures, performance evaluation of the implemented system security are conducted.

Analyzing the Effect of TCP and Server Population on Massively Multiplayer Games

Directory of Open Access Journals (Sweden)

Mirko Suznjevic

2014-01-01

Full Text Available Many Massively Multiplayer Online Role-Playing Games (MMORPGs use TCP flows for communication between the server and the game clients. The utilization of TCP, which was not initially designed for (soft real-time services, has many implications for the competing traffic flows. In this paper we present a series of studies which explore the competition between MMORPG and other traffic flows. For that aim, we first extend a source-based traffic model, based on player’s activities during the day, to also incorporate the impact of the number of players sharing a server (server population on network traffic. Based on real traffic traces, we statistically model the influence of the variation of the server’s player population on the network traffic, depending on the action categories (i.e., types of in-game player behaviour. Using the developed traffic model we prove that while server population only modifies specific action categories, this effect is significant enough to be observed on the overall traffic. We find that TCP Vegas is a good option for competing flows in order not to throttle the MMORPG flows and that TCP SACK is more respectful with game flows than other TCP variants, namely, Tahoe, Reno, and New Reno. Other tests show that MMORPG flows do not significantly reduce their sending window size when competing against UDP flows. Additionally, we study the effect of RTT unfairness between MMORPG flows, showing that it is less important than in the case of network-limited TCP flows.

Dynamic web cache publishing for IaaS clouds using Shoal

International Nuclear Information System (INIS)

Gable, Ian; Chester, Michael; Berghaus, Frank; Leavett-Brown, Colin; Paterson, Michael; Prior, Robert; Sobie, Randall; Taylor, Ryan; Armstrong, Patrick; Charbonneau, Andre

2014-01-01

We have developed a highly scalable application, called Shoal, for tracking and utilizing a distributed set of HTTP web caches. Our application uses the Squid HTTP cache. Squid servers advertise their existence to the Shoal server via AMQP messaging by running Shoal Agent. The Shoal server provides a simple REST interface that allows clients to determine their closest Squid cache. Our goal is to dynamically instantiate Squid caches on IaaS clouds in response to client demand. Shoal provides the VMs on IaaS clouds with the location of the nearest dynamically instantiated Squid Cache

Supporting Adaptation of Wireless Communication Protocols

International Nuclear Information System (INIS)

Dhomeja, L.D.; Soomro, I.A.; Malkani, Y.A.

2016-01-01

Pervasive devices such as mobile phones and PDAs (Personal Digital Assistants) come with different wireless communication capabilities, for example, WiFi (Wireless Fidelity), Bluetooth, IrDA (Infrared), etc. In order for pervasive devices to interact with each other, they need to have matching (alike) communication capabilities, otherwise such heterogeneous devices would not be able to interact with each other. In this paper we address this issue and propose a system that makes devices with heterogeneous wireless communication capabilities communicate with each other. The proposed system supports adaptation of wireless communication protocols through a proxy, which sits between a client and a server, and supports adaptation of wireless communication protocols. Its functionality involves intercepting a request made by a client with a different wireless communication capability (e.g. Bluetooth) from what the server has (e.g. WiFi), connecting to the server and then sending results back to the client. We have tested the system by implementing a messaging service application and running it on the system. The proxy supports all Bluetooth protocols, i.e. OBEX (Object Exchange), L2CAP (Logical Link Control and Adaptation Protocol), RFCOM (Radio Frequency Communication) and WiFi protocol and can run on (J2MW (Java 2 Micro Edition) enabled mobile phones which support both Bluetooth and WiFi capabilities. (author)

Disk Storage Server

CERN Multimedia

This model was a disk storage server used in the Data Centre up until 2012. Each tray contains a hard disk drive (see the 5TB hard disk drive on the main disk display section - this actually fits into one of the trays). There are 16 trays in all per server. There are hundreds of these servers mounted on racks in the Data Centre, as can be seen.

Group-Server Queues

OpenAIRE

Li, Quan-Lin; Ma, Jing-Yu; Xie, Mingzhou; Xia, Li

2017-01-01

By analyzing energy-efficient management of data centers, this paper proposes and develops a class of interesting {\\it Group-Server Queues}, and establishes two representative group-server queues through loss networks and impatient customers, respectively. Furthermore, such two group-server queues are given model descriptions and necessary interpretation. Also, simple mathematical discussion is provided, and simulations are made to study the expected queue lengths, the expected sojourn times ...

OPC Server and BridgeView Application for High Voltage Power Supply Lecroy 1458

CERN Document Server

Swoboda, D; CERN. Geneva

2000-01-01

Abstract The aim of this project was to develop an OPC server to communicate over an RS232 serial line. This communication media is commonly used with commercial instruments. The development was made for a High Voltage power supply in the context of the Alice [1] experiment. In addition, the structured modular concept will allow changing the transmission media or power supply type with little effort. The high voltage power supply should be accessible remotely through a network. OPC[2] is an acronym for OLE[3] for Process Control. OPC is based on the DCOM [3] communication protocol, which allows communication with any computer running a Windows based OS. This standard is widely used in industry to access device data through Windows applications. The concept is based on the client-server architecture. The hardware and the software architecture are described. Subsequently details of the implemented programs are given with emphasis on the possibility to replace parts of the software in order to use differ...

Web-based access to near real-time and archived high-density time-series data: cyber infrastructure challenges & developments in the open-source Waveform Server

Science.gov (United States)

Reyes, J. C.; Vernon, F. L.; Newman, R. L.; Steidl, J. H.

2010-12-01

The Waveform Server is an interactive web-based interface to multi-station, multi-sensor and multi-channel high-density time-series data stored in Center for Seismic Studies (CSS) 3.0 schema relational databases (Newman et al., 2009). In the last twelve months, based on expanded specifications and current user feedback, both the server-side infrastructure and client-side interface have been extensively rewritten. The Python Twisted server-side code-base has been fundamentally modified to now present waveform data stored in cluster-based databases using a multi-threaded architecture, in addition to supporting the pre-existing single database model. This allows interactive web-based access to high-density (broadband @ 40Hz to strong motion @ 200Hz) waveform data that can span multiple years; the common lifetime of broadband seismic networks. The client-side interface expands on it's use of simple JSON-based AJAX queries to now incorporate a variety of User Interface (UI) improvements including standardized calendars for defining time ranges, applying on-the-fly data calibration to display SI-unit data, and increased rendering speed. This presentation will outline the various cyber infrastructure challenges we have faced while developing this application, the use-cases currently in existence, and the limitations of web-based application development.

Web server attack analyzer

OpenAIRE

Mižišin, Michal

2013-01-01

Web server attack analyzer - Abstract The goal of this work was to create prototype of analyzer of injection flaws attacks on web server. Proposed solution combines capabilities of web application firewall and web server log analyzer. Analysis is based on configurable signatures defined by regular expressions. This paper begins with summary of web attacks, followed by detection techniques analysis on web servers, description and justification of selected implementation. In the end are charact...

Implementing Citrix XenServer Quickstarter

CERN Document Server

Ahmed, Gohar

2013-01-01

Implementing Citrix XenServer Quick Starter is a practical, hands-on guide that will help you get started with the Citrix XenServer Virtualization technology with easy-to-follow instructions.Implementing Citrix XenServer Quick Starter is for system administrators who have little to no information on virtualization and specifically Citrix XenServer Virtualization. If you're managing a lot of physical servers and are tired of installing, deploying, updating, and managing physical machines on a daily basis over and over again, then you should probably explore your option of XenServer Virtualizati

Server virtualization solutions

OpenAIRE

Jonasts, Gusts

2012-01-01

Currently in the information technology sector that is responsible for a server infrastructure is a huge development in the field of server virtualization on x86 computer architecture. As a prerequisite for such a virtualization development is growth in server productivity and underutilization of available computing power. Several companies in the market are working on two virtualization architectures – hypervizor and hosting. In this paper several of virtualization products that use host...

Web Server Embedded System

Directory of Open Access Journals (Sweden)

Adharul Muttaqin

2014-07-01

Full Text Available Abstrak Embedded sistem saat ini menjadi perhatian khusus pada teknologi komputer, beberapa sistem operasi linux dan web server yang beraneka ragam juga sudah dipersiapkan untuk mendukung sistem embedded, salah satu aplikasi yang dapat digunakan dalam operasi pada sistem embedded adalah web server. Pemilihan web server pada lingkungan embedded saat ini masih jarang dilakukan, oleh karena itu penelitian ini dilakukan dengan menitik beratkan pada dua buah aplikasi web server yang tergolong memiliki fitur utama yang menawarkan “keringanan” pada konsumsi CPU maupun memori seperti Light HTTPD dan Tiny HTTPD. Dengan menggunakan parameter thread (users, ramp-up periods, dan loop count pada stress test embedded system, penelitian ini menawarkan solusi web server manakah diantara Light HTTPD dan Tiny HTTPD yang memiliki kecocokan fitur dalam penggunaan embedded sistem menggunakan beagleboard ditinjau dari konsumsi CPU dan memori. Hasil penelitian menunjukkan bahwa dalam hal konsumsi CPU pada beagleboard embedded system lebih disarankan penggunaan Light HTTPD dibandingkan dengan tiny HTTPD dikarenakan terdapat perbedaan CPU load yang sangat signifikan antar kedua layanan web tersebut Kata kunci: embedded system, web server Abstract Embedded systems are currently of particular concern in computer technology, some of the linux operating system and web server variegated also prepared to support the embedded system, one of the applications that can be used in embedded systems are operating on the web server. Selection of embedded web server on the environment is still rarely done, therefore this study was conducted with a focus on two web application servers belonging to the main features that offer a "lightness" to the CPU and memory consumption as Light HTTPD and Tiny HTTPD. By using the parameters of the thread (users, ramp-up periods, and loop count on a stress test embedded systems, this study offers a solution of web server which between the Light

Multiple Comorbidities and Interest in Research Participation Among Clients of a Nonprofit Food Distribution Site.

Science.gov (United States)

Higashi, Robin T; Craddock Lee, Simon J; Leonard, Tammy; Cuate, Erica L; Cole, Jay; Pruitt, Sandi L

2015-10-01

Persons accessing food from nonprofit distribution sites face numerous challenges and typically have significant unmet health needs. However, given limited and intermittent healthcare system engagement, this vulnerable population is underrepresented in clinical research. We sought to better understand the health needs of a nonclinical population to inform future research and interventions. Focus groups were conducted in English (n = 4) and Spanish (n = 4) with clients of Crossroads Community Services (CCS), the largest distributor of North Texas Food Bank. Discussions probed participants' health status, healthcare utilization, understanding and utilization of mammography, and attitudes toward participation in research. Participants included 42 CCS clients, primarily Hispanic or African American women. Participants reported multiple comorbid conditions among household members, yet utilization of health services was often limited by cost. The majority expressed interest in participating in research to communicate their health concerns and obtain emotional support. CCS clients represent a high-need, under-reached population willing to engage in health-related research that affords them opportunity to connect with peers in group settings and obtain information to improve management of daily life challenges. The Community Assistance Research (CARe) Initiative, a community-academic collaboration, establishes a much-needed opportunity for ongoing clinical research and intervention among this underserved population. © 2015 Wiley Periodicals, Inc.

EarthServer - an FP7 project to enable the web delivery and analysis of 3D/4D models

Science.gov (United States)

Laxton, John; Sen, Marcus; Passmore, James

2013-04-01

EarthServer aims at open access and ad-hoc analytics on big Earth Science data, based on the OGC geoservice standards Web Coverage Service (WCS) and Web Coverage Processing Service (WCPS). The WCS model defines "coverages" as a unifying paradigm for multi-dimensional raster data, point clouds, meshes, etc., thereby addressing a wide range of Earth Science data including 3D/4D models. WCPS allows declarative SQL-style queries on coverages. The project is developing a pilot implementing these standards, and will also investigate the use of GeoSciML to describe coverages. Integration of WCPS with XQuery will in turn allow coverages to be queried in combination with their metadata and GeoSciML description. The unified service will support navigation, extraction, aggregation, and ad-hoc analysis on coverage data from SQL. Clients will range from mobile devices to high-end immersive virtual reality, and will enable 3D model visualisation using web browser technology coupled with developing web standards. EarthServer is establishing open-source client and server technology intended to be scalable to Petabyte/Exabyte volumes, based on distributed processing, supercomputing, and cloud virtualization. Implementation will be based on the existing rasdaman server technology developed. Services using rasdaman technology are being installed serving the atmospheric, oceanographic, geological, cryospheric, planetary and general earth observation communities. The geology service (http://earthserver.bgs.ac.uk/) is being provided by BGS and at present includes satellite imagery, superficial thickness data, onshore DTMs and 3D models for the Glasgow area. It is intended to extend the data sets available to include 3D voxel models. Use of the WCPS standard allows queries to be constructed against single or multiple coverages. For example on a single coverage data for a particular area can be selected or data with a particular range of pixel values. Queries on multiple surfaces can be

Transient queue-size distribution in a finite-capacity queueing system with server breakdowns and Bernoulli feedback

Science.gov (United States)

Kempa, Wojciech M.

2017-12-01

A finite-capacity queueing system with server breakdowns is investigated, in which successive exponentially distributed failure-free times are followed by repair periods. After the processing a customer may either rejoin the queue (feedback) with probability q, or definitely leave the system with probability 1 - q. The system of integral equations for transient queue-size distribution, conditioned by the initial level of buffer saturation, is build. The solution of the corresponding system written for Laplace transforms is found using the linear algebraic approach. The considered queueing system can be successfully used in modelling production lines with machine failures, in which the parameter q may be considered as a typical fraction of items demanding corrections. Morever, this queueing model can be applied in the analysis of real TCP/IP performance, where q stands for the fraction of packets requiring retransmission.

Professional SQL Server 2005 administration

CERN Document Server

Knight, Brian; Snyder, Wayne; Armand, Jean-Claude; LoForte, Ross; Ji, Haidong

2007-01-01

SQL Server 2005 is the largest leap forward for SQL Server since its inception. With this update comes new features that will challenge even the most experienced SQL Server DBAs. Written by a team of some of the best SQL Server experts in the industry, this comprehensive tutorial shows you how to navigate the vastly changed landscape of the SQL Server administration. Drawing on their own first-hand experiences to offer you best practices, unique tips and tricks, and useful workarounds, the authors help you handle even the most difficult SQL Server 2005 administration issues, including blockin

QlikView Server and Publisher

CERN Document Server

Redmond, Stephen

2014-01-01

This is a comprehensive guide with a step-by-step approach that enables you to host and manage servers using QlikView Server and QlikView Publisher.If you are a server administrator wanting to learn about how to deploy QlikView Server for server management,analysis and testing, and QlikView Publisher for publishing of business content then this is the perfect book for you. No prior experience with QlikView is expected.

Database architectures for Space Telescope Science Institute

Science.gov (United States)

Lubow, Stephen

1993-08-01

At STScI nearly all large applications require database support. A general purpose architecture has been developed and is in use that relies upon an extended client-server paradigm. Processing is in general distributed across three processes, each of which generally resides on its own processor. Database queries are evaluated on one such process, called the DBMS server. The DBMS server software is provided by a database vendor. The application issues database queries and is called the application client. This client uses a set of generic DBMS application programming calls through our STDB/NET programming interface. Intermediate between the application client and the DBMS server is the STDB/NET server. This server accepts generic query requests from the application and converts them into the specific requirements of the DBMS server. In addition, it accepts query results from the DBMS server and passes them back to the application. Typically the STDB/NET server is local to the DBMS server, while the application client may be remote. The STDB/NET server provides additional capabilities such as database deadlock restart and performance monitoring. This architecture is currently in use for some major STScI applications, including the ground support system. We are currently investigating means of providing ad hoc query support to users through the above architecture. Such support is critical for providing flexible user interface capabilities. The Universal Relation advocated by Ullman, Kernighan, and others appears to be promising. In this approach, the user sees the entire database as a single table, thereby freeing the user from needing to understand the detailed schema. A software layer provides the translation between the user and detailed schema views of the database. However, many subtle issues arise in making this transformation. We are currently exploring this scheme for use in the Hubble Space Telescope user interface to the data archive system (DADS).

P-wave scattering and the distribution of heterogeneity around Etna volcano

Directory of Open Access Journals (Sweden)

Toni Zieger

2016-09-01

Full Text Available Volcanoes and fault zones are areas of increased heterogeneity in the Earth crust that leads to strong scattering of seismic waves. For the understanding of the volcanic structure and the role of attenuation and scattering processes it is important to investigate the distribution of heterogeneity. We used the signals of air-gun shots to investigate the distribution of heterogeneity around Mount Etna. We devise a new methodology that is based on the coda energy ratio which we define as the ratio between the energy of the direct P-wave and the energy in a later coda window. This is based on the basic assumption that scattering caused by heterogeneity removes energy from the direct P-waves. We show that measurements of the energy ratio are stable with respect to changes of the details of the time windows definitions. As an independent proxy of the scattering strength along the ray path we measure the peak delay time of the direct P-wave. The peak delay time is well correlated with the coda energy ratio. We project the observation in the directions of the incident rays at the stations. Most notably is an area with increased wave scattering in the volcano and east of it. The strong heterogeneity found supports earlier observations and confirms the possibility to use P-wave sources for the determination of scattering properties. We interpret the extension of the highly heterogeneous zone towards the east as a potential signature of inelastic deformation processes induced by the eastward sliding of flank of the volcano.

A uniform approach for programming distributed heterogeneous computing systems.

Science.gov (United States)

Grasso, Ivan; Pellegrini, Simone; Cosenza, Biagio; Fahringer, Thomas

2014-12-01

Large-scale compute clusters of heterogeneous nodes equipped with multi-core CPUs and GPUs are getting increasingly popular in the scientific community. However, such systems require a combination of different programming paradigms making application development very challenging. In this article we introduce libWater, a library-based extension of the OpenCL programming model that simplifies the development of heterogeneous distributed applications. libWater consists of a simple interface, which is a transparent abstraction of the underlying distributed architecture, offering advanced features such as inter-context and inter-node device synchronization. It provides a runtime system which tracks dependency information enforced by event synchronization to dynamically build a DAG of commands, on which we automatically apply two optimizations: collective communication pattern detection and device-host-device copy removal. We assess libWater's performance in three compute clusters available from the Vienna Scientific Cluster, the Barcelona Supercomputing Center and the University of Innsbruck, demonstrating improved performance and scaling with different test applications and configurations.

NOAA Operational Model Archive Distribution System (NOMADS): High Availability Applications for Reliable Real Time Access to Operational Model Data

Science.gov (United States)

Alpert, J. C.; Wang, J.

2009-12-01

To reduce the impact of natural hazards and environmental changes, the National Centers for Environmental Prediction (NCEP) provide first alert and a preferred partner for environmental prediction services, and represents a critical national resource to operational and research communities affected by climate, weather and water. NOMADS is now delivering high availability services as part of NOAA’s official real time data dissemination at its Web Operations Center (WOC) server. The WOC is a web service used by organizational units in and outside NOAA, and acts as a data repository where public information can be posted to a secure and scalable content server. A goal is to foster collaborations among the research and education communities, value added retailers, and public access for science and development efforts aimed at advancing modeling and GEO-related tasks. The user (client) executes what is efficient to execute on the client and the server efficiently provides format independent access services. Client applications can execute on the server, if it is desired, but the same program can be executed on the client side with no loss of efficiency. In this way this paradigm lends itself to aggregation servers that act as servers of servers listing, searching catalogs of holdings, data mining, and updating information from the metadata descriptions that enable collections of data in disparate places to be simultaneously accessed, with results processed on servers and clients to produce a needed answer. The services used to access the operational model data output are the Open-source Project for a Network Data Access Protocol (OPeNDAP), implemented with the Grid Analysis and Display System (GrADS) Data Server (GDS), and applications for slicing, dicing and area sub-setting the large matrix of real time model data holdings. This approach insures an efficient use of computer resources because users transmit/receive only the data necessary for their tasks including

Design, Implementation and Testing of a Tiny Multi-Threaded DNS64 Server

Directory of Open Access Journals (Sweden)

Gábor Lencse

2016-03-01

Full Text Available DNS64 is going to be an important service (together with NAT64 in the upcoming years of the IPv6 transition enabling the clients having only IPv6 addresses to reach the servers having only IPv4 addresses (the majority of the servers on the Internet today. This paper describes the design, implementation and functional testing of MTD64, a flexible, easy to use, multi-threaded DNS64 proxy published as a free software under the GPLv2 license. All the theoretical background is introduced including the DNS message format, the operation of the DNS64 plus NAT64 solution and the construction of the IPv4-embedded IPv6 addresses. Our design decisions are fully disclosed from the high level ones to the details. Implementation is introduced at high level only as the details can be found in the developer documentation. The most important parts of a through functional testing are included as well as the results of some basic performance comparison with BIND.

Distributed processing and network of data acquisition and diagnostics control for Large Helical Device (LHD)

International Nuclear Information System (INIS)

Nakanishi, H.; Kojima, M.; Hidekuma, S.

1997-11-01

The LHD (Large Helical Device) data processing system has been designed in order to deal with the huge amount of diagnostics data of 600-900 MB per 10-second short-pulse experiment. It prepares the first plasma experiment in March 1998. The recent increase of the data volume obliged to adopt the fully distributed system structure which uses multiple data transfer paths in parallel and separates all of the computer functions into clients and servers. The fundamental element installed for every diagnostic device consists of two kinds of server computers; the data acquisition PC/Windows NT and the real-time diagnostics control VME/VxWorks. To cope with diversified kinds of both device control channels and diagnostics data, the object-oriented method are utilized wholly for the development of this system. It not only reduces the development burden, but also widen the software portability and flexibility. 100Mbps EDDI-based fast networks will re-integrate the distributed server computers so that they can behave as one virtual macro-machine for users. Network methods applied for the LHD data processing system are completely based on the TCP/IP internet technology, and it provides the same accessibility to the remote collaborators as local participants can operate. (author)

Advanced 3-D analysis, client-server systems, and cloud computing-Integration of cardiovascular imaging data into clinical workflows of transcatheter aortic valve replacement.

Science.gov (United States)

Schoenhagen, Paul; Zimmermann, Mathis; Falkner, Juergen

2013-06-01

Degenerative aortic stenosis is highly prevalent in the aging populations of industrialized countries and is associated with poor prognosis. Surgical valve replacement has been the only established treatment with documented improvement of long-term outcome. However, many of the older patients with aortic stenosis (AS) are high-risk or ineligible for surgery. For these patients, transcatheter aortic valve replacement (TAVR) has emerged as a treatment alternative. The TAVR procedure is characterized by a lack of visualization of the operative field. Therefore, pre- and intra-procedural imaging is critical for patient selection, pre-procedural planning, and intra-operative decision-making. Incremental to conventional angiography and 2-D echocardiography, multidetector computed tomography (CT) has assumed an important role before TAVR. The analysis of 3-D CT data requires extensive post-processing during direct interaction with the dataset, using advance analysis software. Organization and storage of the data according to complex clinical workflows and sharing of image information have become a critical part of these novel treatment approaches. Optimally, the data are integrated into a comprehensive image data file accessible to multiple groups of practitioners across the hospital. This creates new challenges for data management requiring a complex IT infrastructure, spanning across multiple locations, but is increasingly achieved with client-server solutions and private cloud technology. This article describes the challenges and opportunities created by the increased amount of patient-specific imaging data in the context of TAVR.

System and Method for Providing a Climate Data Analytic Services Application Programming Interface Distribution Package

Science.gov (United States)

Schnase, John L. (Inventor); Duffy, Daniel Q. (Inventor); Tamkin, Glenn S. (Inventor)

2016-01-01

A system, method and computer-readable storage devices for providing a climate data analytic services application programming interface distribution package. The example system can provide various components. The system provides a climate data analytic services application programming interface library that enables software applications running on a client device to invoke the capabilities of a climate data analytic service. The system provides a command-line interface that provides a means of interacting with a climate data analytic service by issuing commands directly to the system's server interface. The system provides sample programs that call on the capabilities of the application programming interface library and can be used as templates for the construction of new client applications. The system can also provide test utilities, build utilities, service integration utilities, and documentation.

PONGO: a web server for multiple predictions of all-alpha transmembrane proteins

DEFF Research Database (Denmark)

Amico, M.; Finelli, M.; Rossi, I.

2006-01-01

of the organism and more importantly with the same sequence profile for a given sequence when required. Here we present a new web server that incorporates the state-of-the-art topology predictors in a single framework, so that putative users can interactively compare and evaluate four predictions simultaneously...... for a given sequence. Together with the predicted topology, the server also displays a signal peptide prediction determined with SPEP. The PONGO web server is available at http://pongo.biocomp.unibo.it/pongo .......The annotation efforts of the BIOSAPIENS European Network of Excellence have generated several distributed annotation systems (DAS) with the aim of integrating Bioinformatics resources and annotating metazoan genomes ( http://www.biosapiens.info/ ). In this context, the PONGO DAS server ( http...

Supporting the Loewenstein occupational therapy cognitive assessment using distributed user interfaces.

Science.gov (United States)

Tesoriero, Ricardo; Gallud Lazaro, Jose A; Altalhi, Abdulrahman H

2017-02-01

Improve the quantity and quality of information obtained from traditional Loewenstein Occupational Therapy Cognitive Assessment Battery systems to monitor the evolution of patients' rehabilitation process as well as to compare different rehabilitation therapies. The system replaces traditional artefacts with virtual versions of them to take advantage of cutting edge interaction technology. The system is defined as a Distributed User Interface (DUI) supported by a display ecosystem, including mobile devices as well as multi-touch surfaces. Due to the heterogeneity of the devices involved in the system, the software technology is based on a client-server architecture using the Web as the software platform. The system provides therapists with information that is not available (or it is very difficult to gather) using traditional technologies (i.e. response time measurements, object tracking, information storage and retrieval facilities, etc.). The use of DUIs allows therapists to gather information that is unavailable using traditional assessment methods as well as adapt the system to patients' profile to increase the range of patients that are able to take this assessment. Implications for Rehabilitation Using a Distributed User Interface environment to carry out LOTCAs improves the quality of the information gathered during the rehabilitation assessment. This system captures physical data regarding patient's interaction during the assessment to improve the rehabilitation process analysis. Allows professionals to adapt the assessment procedure to create different versions according to patients' profile. Improves the availability of patients' profile information to therapists to adapt the assessment procedure.

Distributed control system for NSC tandem-LINAC

International Nuclear Information System (INIS)

Ajith Kumar, B.P.; Subrahmaniam, E.T.; Singh, Kundan

2001-01-01

The new control system for the tandem-LINAC accelerator system at Nuclear Science Centre (NSC), runs on a network of Pentiums under the LINUX operating system. Some of the computers are interfaced to the devices of the accelerator, using CAMAC, and run a server program. On the same network there are machines providing the operator interface, by running the client program. The client computers use the x-window graphics and shaft encoder knobs interfaced to them to provide the operator interface. The system supports the monitoring and controlling of all the accelerator parameters including the beam profile monitors, from any of the clients. (author)

Mastering Microsoft Exchange Server 2010

CERN Document Server

McBee, Jim

2010-01-01

A top-selling guide to Exchange Server-now fully updated for Exchange Server 2010. Keep your Microsoft messaging system up to date and protected with the very newest version, Exchange Server 2010, and this comprehensive guide. Whether you're upgrading from Exchange Server 2007 SP1 or earlier, installing for the first time, or migrating from another system, this step-by-step guide provides the hands-on instruction, practical application, and real-world advice you need.: Explains Microsoft Exchange Server 2010, the latest release of Microsoft's messaging system that protects against spam and vir

Optimal control of a server farm

NARCIS (Netherlands)

Adan, I.J.B.F.; Kulkarni, V.G.; Wijk, van A.C.C.

2013-01-01

We consider a server farm consisting of ample exponential servers, that serve a Poisson stream of arriving customers. Each server can be either busy, idle or off. An arriving customer will immediately occupy an idle server, if there is one, and otherwise, an off server will be turned on and start

TCP isoeffect analysis using a heterogeneous distribution of radiosensitivity

International Nuclear Information System (INIS)

Carlone, Marco; Wilkins, David; Nyiri, Balazs; Raaphorst, Peter

2004-01-01

A formula for the α/β ratio is derived using the heterogeneous (population averaged) tumor control model. This formula is nearly identical to the formula obtained using the homogeneous (individual) tumor control model, but the new formula includes extra terms showing that the α/β ratio, the ratio of the mean value of α divided by the mean value of β that would be observed in a patient population, explicitly depends on the survival level and heterogeneity. The magnitude of this correction is estimated for prostate cancer, and this appears to raise the mean value of the ratio estimate by about 20%. The method also allows investigation of confidence limits for α/β based on a population distribution of radiosensitivity. For a widely heterogeneous population, the upper 95% confidence interval for the α/β ratio can be as high as 7.3 Gy, even though the population mean is between 2.3 and 2.6 Gy

Monte Carlo Estimation of Absorbed Dose Distributions Obtained from Heterogeneous 106Ru Eye Plaques.

Science.gov (United States)

Zaragoza, Francisco J; Eichmann, Marion; Flühs, Dirk; Sauerwein, Wolfgang; Brualla, Lorenzo

2017-09-01

The distribution of the emitter substance in 106 Ru eye plaques is usually assumed to be homogeneous for treatment planning purposes. However, this distribution is never homogeneous, and it widely differs from plaque to plaque due to manufacturing factors. By Monte Carlo simulation of radiation transport, we study the absorbed dose distribution obtained from the specific CCA1364 and CCB1256 106 Ru plaques, whose actual emitter distributions were measured. The idealized, homogeneous CCA and CCB plaques are also simulated. The largest discrepancy in depth dose distribution observed between the heterogeneous and the homogeneous plaques was 7.9 and 23.7% for the CCA and CCB plaques, respectively. In terms of isodose lines, the line referring to 100% of the reference dose penetrates 0.2 and 1.8 mm deeper in the case of heterogeneous CCA and CCB plaques, respectively, with respect to the homogeneous counterpart. The observed differences in absorbed dose distributions obtained from heterogeneous and homogeneous plaques are clinically irrelevant if the plaques are used with a lateral safety margin of at least 2 mm. However, these differences may be relevant if the plaques are used in eccentric positioning.

Microsoft SQL Server 2012 bible

CERN Document Server

Jorgensen, Adam; LeBlanc, Patrick; Cherry, Denny; Nelson, Aaron

2012-01-01

Harness the powerful new SQL Server 2012 Microsoft SQL Server 2012 is the most significant update to this product since 2005, and it may change how database administrators and developers perform many aspects of their jobs. If you're a database administrator or developer, Microsoft SQL Server 2012 Bible teaches you everything you need to take full advantage of this major release. This detailed guide not only covers all the new features of SQL Server 2012, it also shows you step by step how to develop top-notch SQL Server databases and new data connections and keep your databases performing at p

Heterogeneous Data Fusion Method to Estimate Travel Time Distributions in Congested Road Networks.

Science.gov (United States)

Shi, Chaoyang; Chen, Bi Yu; Lam, William H K; Li, Qingquan

2017-12-06

Travel times in congested urban road networks are highly stochastic. Provision of travel time distribution information, including both mean and variance, can be very useful for travelers to make reliable path choice decisions to ensure higher probability of on-time arrival. To this end, a heterogeneous data fusion method is proposed to estimate travel time distributions by fusing heterogeneous data from point and interval detectors. In the proposed method, link travel time distributions are first estimated from point detector observations. The travel time distributions of links without point detectors are imputed based on their spatial correlations with links that have point detectors. The estimated link travel time distributions are then fused with path travel time distributions obtained from the interval detectors using Dempster-Shafer evidence theory. Based on fused path travel time distribution, an optimization technique is further introduced to update link travel time distributions and their spatial correlations. A case study was performed using real-world data from Hong Kong and showed that the proposed method obtained accurate and robust estimations of link and path travel time distributions in congested road networks.

Upper Bounds on Performance Measures of Heterogeneous // Queues

Directory of Open Access Journals (Sweden)

F. S. Q. Alves

2011-01-01

Full Text Available In many real-life queueing systems, the servers are often heterogeneous, namely they work at different rates. This paper provides a simple method to compute tight upper bounds on two important performance measures of single-class heterogeneous multi-server Markovian queueing systems, namely the average number in queue and the average waiting time in queue. This method is based on an expansion of the state space that is followed by an approximate reduction of the state space, only considering the most probable states. In most cases tested, we were able to approximate the actual behavior of the system with smaller errors than those obtained from traditional homogeneous multiserver Markovian queues, as shown by GPSS simulations. In addition, we have correlated the quality of the approximation with the degree of heterogeneity of the system, which was evaluated using its Gini index. Finally, we have shown that the bounds are robust and still useful, even considering quite different allocation strategies. A large number of simulation results show the accuracy of the proposed method that is better than that of classical homogeneous multiserver Markovian formulae in many situations.

Linux Server Security

CERN Document Server

Bauer, Michael D

2005-01-01

Linux consistently appears high up in the list of popular Internet servers, whether it's for the Web, anonymous FTP, or general services such as DNS and delivering mail. But security is the foremost concern of anyone providing such a service. Any server experiences casual probe attempts dozens of time a day, and serious break-in attempts with some frequency as well. This highly regarded book, originally titled Building Secure Servers with Linux, combines practical advice with a firm knowledge of the technical tools needed to ensure security. The book focuses on the most common use of Linux--

Windows server cookbook for Windows server 2003 and Windows 2000

CERN Document Server

Allen, Robbie

2005-01-01

This practical reference guide offers hundreds of useful tasks for managing Windows 2000 and Windows Server 2003, Microsoft's latest server. These concise, on-the-job solutions to common problems are certain to save you many hours of time searching through Microsoft documentation. Topics include files, event logs, security, DHCP, DNS, backup/restore, and more

Synchronization resources in heterogeneous environments: Time-sharing, real-time and Java

International Nuclear Information System (INIS)

Pereira, A.; Vega, J.; Pacios, L.; Sanchez, E.; Portas, A.

2006-01-01

The asynchronous event distribution system (AEDS) was built to provide synchronization resources within the TJ-II local area network. It is a software system developed to add 'soft synchronization' capabilities to the TJ-II data acquisition, control and analysis environments. 'Soft synchronization' signifies that AEDS is not a real-time system. In fact, AEDS is based on TCP/IP over ETHERNET networks. However, its response time is adequate for practical purposes when synchronization requirements can support some delay between event dispatch and message reception. Event broadcasters (or synchronization servers in AEDS terminology) are Windows computers. Destination computers (or synchronization clients) were also Windows machines in the first version of AEDS. However, this fact imposed a very important limitation on synchronization capabilities. To overcome this situation, synchronization clients for different environments have been added to AEDS: for time-sharing operating systems (Unix and Linux), real-time operating systems (OS-9 and VxWorks) and Java applications. These environments have different synchronization primitives, requiring different approaches to provide the required uniform functionality. This has been achieved with POSIX thread library synchronization primitives (mutex and condition variables) on Unix/Linux systems, IPC mechanisms for concurrent processes on OS-9 and VxWorks real-time operating systems, and 'synchronized-wait/notify' primitives on Java virtual machines

Computer simulation of the interplay between fractal structures and surrounding heterogeneous multifractal distributions. Applications

OpenAIRE

Martin Martin, Miguel Angel; Reyes Castro, Miguel E.; Taguas Coejo, Fco. Javier

2014-01-01

In a large number of physical, biological and environmental processes interfaces with high irregular geometry appear separating media (phases) in which the heterogeneity of constituents is present. In this work the quantification of the interplay between irregular structures and surrounding heterogeneous distributions in the plane is made For a geometric set image and a mass distribution (measure) image supported in image, being image, the mass image gives account of the interplay between th...

Learning SQL Server Reporting Services 2012

CERN Document Server

Krishnaswamy, Jayaram

2013-01-01

The book is packed with clear instructions and plenty of screenshots, providing all the support and guidance you will need as you begin to generate reports with SQL Server 2012 Reporting Services.This book is for those who are new to SQL Server Reporting Services 2012 and aspiring to create and deploy cutting edge reports. This book is for report developers, report authors, ad-hoc report authors and model developers, and Report Server and SharePoint Server Integrated Report Server administrators. Minimal knowledge of SQL Server is assumed and SharePoint experience would be helpful.

Effects of heterogeneous wealth distribution on public cooperation with collective risk

Science.gov (United States)

Wang, Jing; Fu, Feng; Wang, Long

2010-07-01

The distribution of wealth among individuals in real society can be well described by the Pareto principle or “80-20 rule.” How does such heterogeneity in initial wealth distribution affect the emergence of public cooperation, when individuals, the rich and the poor, engage in a collective-risk enterprise, not to gain a profit but to avoid a potential loss? Here we address this issue by studying a simple but effective model based on threshold public goods games. We analyze the evolutionary dynamics for two distinct scenarios, respectively: one with fair sharers versus defectors and the other with altruists versus defectors. For both scenarios, particularly, we in detail study the dynamics of the population with dichotomic initial wealth—the rich versus the poor. Moreover, we demonstrate the possible steady compositions of the population and provide the conditions for stability of these steady states. We prove that in a population with heterogeneous wealth distribution, richer individuals are more likely to cooperate than poorer ones. Participants with lower initial wealth may choose to cooperate only if all players richer than them are cooperators. The emergence of pubic cooperation largely relies on rich individuals. Furthermore, whenever the wealth gap between the rich and the poor is sufficiently large, cooperation of a few rich individuals can substantially elevate the overall level of social cooperation, which is in line with the well-known Pareto principle. Our work may offer an insight into the emergence of cooperative behavior in real social situations where heterogeneous distribution of wealth among individual is omnipresent.

Effects of heterogeneous wealth distribution on public cooperation with collective risk.

Science.gov (United States)

Wang, Jing; Fu, Feng; Wang, Long

2010-07-01

The distribution of wealth among individuals in real society can be well described by the Pareto principle or "80-20 rule." How does such heterogeneity in initial wealth distribution affect the emergence of public cooperation, when individuals, the rich and the poor, engage in a collective-risk enterprise, not to gain a profit but to avoid a potential loss? Here we address this issue by studying a simple but effective model based on threshold public goods games. We analyze the evolutionary dynamics for two distinct scenarios, respectively: one with fair sharers versus defectors and the other with altruists versus defectors. For both scenarios, particularly, we in detail study the dynamics of the population with dichotomic initial wealth-the rich versus the poor. Moreover, we demonstrate the possible steady compositions of the population and provide the conditions for stability of these steady states. We prove that in a population with heterogeneous wealth distribution, richer individuals are more likely to cooperate than poorer ones. Participants with lower initial wealth may choose to cooperate only if all players richer than them are cooperators. The emergence of pubic cooperation largely relies on rich individuals. Furthermore, whenever the wealth gap between the rich and the poor is sufficiently large, cooperation of a few rich individuals can substantially elevate the overall level of social cooperation, which is in line with the well-known Pareto principle. Our work may offer an insight into the emergence of cooperative behavior in real social situations where heterogeneous distribution of wealth among individual is omnipresent.

Study on distributed generation algorithm of variable precision concept lattice based on ontology heterogeneous database

Science.gov (United States)

WANG, Qingrong; ZHU, Changfeng

2017-06-01

Integration of distributed heterogeneous data sources is the key issues under the big data applications. In this paper the strategy of variable precision is introduced to the concept lattice, and the one-to-one mapping mode of variable precision concept lattice and ontology concept lattice is constructed to produce the local ontology by constructing the variable precision concept lattice for each subsystem, and the distributed generation algorithm of variable precision concept lattice based on ontology heterogeneous database is proposed to draw support from the special relationship between concept lattice and ontology construction. Finally, based on the standard of main concept lattice of the existing heterogeneous database generated, a case study has been carried out in order to testify the feasibility and validity of this algorithm, and the differences between the main concept lattice and the standard concept lattice are compared. Analysis results show that this algorithm above-mentioned can automatically process the construction process of distributed concept lattice under the heterogeneous data sources.

Electronic Commerce -RE-SONANCE---IOct-ob-er

Indian Academy of Sciences (India)

and the emergence of a number of Internet Service Providers. (lSPs) who ..... may be a distributed client/server type system with each office being a client and the .... called denial of service in which a large number of frivolous enquiries are ...

Federal Emergency Management Information System (FEMIS) system administration guide, version 1.4.5

Energy Technology Data Exchange (ETDEWEB)

Arp, J.A.; Burnett, R.A.; Carter, R.J. [and others

1998-06-26

The Federal Emergency Management Information Systems (FEMIS) is an emergency management planning and response tool that was developed by the Pacific Northwest National Laboratory (PNNL) under the direction of the US Army Chemical Biological Defense Command. The FEMIS System Administration Guide provides information necessary for the system administrator to maintain the FEMIS system. The FEMIS system is designed for a single Chemical Stockpile Emergency Preparedness Program (CSEPP) site that has multiple Emergency Operations Centers (EOCs). Each EOC has personal computers (PCs) that emergency planners and operations personnel use to do their jobs. These PCs are connected via a local area network (LAN) to servers that provide EOC-wide services. Each EOC is interconnected to other EOCs via a Wide Area Network (WAN). Thus, FEMIS is an integrated software product that resides on client/server computer architecture. The main body of FEMIS software, referred to as the FEMIS Application Software, resides on the PC client(s) and is directly accessible to emergency management personnel. The remainder of the FEMIS software, referred to as the FEMIS Support Software, resides on the UNIX server. The Support Software provides the communication, data distribution, and notification functionality necessary to operate FEMIS in a networked, client/server environment. The UNIX server provides an Oracle relational database management system (RDBMS) services, ARC/INFO GIS (optional) capabilities, and basic file management services. PNNL developed utilities that reside on the server include the Notification Service, the Command Service that executes the evacuation model, and AutoRecovery. To operate FEMIS, the Application Software must have access to a site specific FEMIS emergency management database. Data that pertains to an individual EOC`s jurisdiction is stored on the EOC`s local server. Information that needs to be accessible to all EOCs is automatically distributed by the FEMIS

MCTBI: a web server for predicting metal ion effects in RNA structures.

Science.gov (United States)

Sun, Li-Zhen; Zhang, Jing-Xiang; Chen, Shi-Jie

2017-08-01

Metal ions play critical roles in RNA structure and function. However, web servers and software packages for predicting ion effects in RNA structures are notably scarce. Furthermore, the existing web servers and software packages mainly neglect ion correlation and fluctuation effects, which are potentially important for RNAs. We here report a new web server, the MCTBI server (http://rna.physics.missouri.edu/MCTBI), for the prediction of ion effects for RNA structures. This server is based on the recently developed MCTBI, a model that can account for ion correlation and fluctuation effects for nucleic acid structures and can provide improved predictions for the effects of metal ions, especially for multivalent ions such as Mg 2+ effects, as shown by extensive theory-experiment test results. The MCTBI web server predicts metal ion binding fractions, the most probable bound ion distribution, the electrostatic free energy of the system, and the free energy components. The results provide mechanistic insights into the role of metal ions in RNA structure formation and folding stability, which is important for understanding RNA functions and the rational design of RNA structures. © 2017 Sun et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Beginning Microsoft SQL Server 2012 Programming

CERN Document Server

Atkinson, Paul

2012-01-01

Get up to speed on the extensive changes to the newest release of Microsoft SQL Server The 2012 release of Microsoft SQL Server changes how you develop applications for SQL Server. With this comprehensive resource, SQL Server authority Robert Vieira presents the fundamentals of database design and SQL concepts, and then shows you how to apply these concepts using the updated SQL Server. Publishing time and date with the 2012 release, Beginning Microsoft SQL Server 2012 Programming begins with a quick overview of database design basics and the SQL query language and then quickly proceeds to sho

Analysis of the asymmetrical shortest two-server queueing model

NARCIS (Netherlands)

J.W. Cohen

1995-01-01

textabstractThis study presents the analytic solution for the asymmetrical two-server queueing model with arriving customers joining the shorter queue for the case with Poisson arrivals and negative exponentially distributed service times. The bivariate generating function of the stationary joint

Characterizing fentanyl use in methadone-maintained clients.

Science.gov (United States)

Arfken, Cynthia L; Suchanek, Jessica; Greenwald, Mark K

2017-04-01

Deaths attributed to fentanyl have increased in the United States. However, little is known about fentanyl use among substance abuse treatment clients. To fill this gap, we assessed prevalence of fentanyl exposure, characteristics of clients testing positive for fentanyl, other substances detected concurrently or simultaneously with fentanyl, and clients' perception of how many people are actively seeking to use fentanyl. A retrospective chart review was conducted of all clients at one methadone maintenance treatment clinic between January 2015 and May 2016 in Wayne County, Michigan. Urine drug screens (UDS) including fentanyl (and its metabolite norfentanyl) were conducted clinically. To obtain additional data, 113 clients in this clinic subsequently completed an anonymous survey. Of 368 unique clients with UDS, 38.0% had at least one and 26.1% had ≥2 fentanyl-positive UDS results. None had a fentanyl prescription. Clients ever testing positive for fentanyl were significantly (pFentanyl-positive UDS results coincided most commonly with metabolites of cocaine- and heroin-positive UDS results. Of the anonymously surveyed clients, most (67.3%) reported they did not know anyone seeking fentanyl, a proportion significantly higher than for heroin, cocaine, alprazolam, hydrocodone and morphine. Fentanyl was commonly detected during this period with some clients having multiple fentanyl-positive UDS. Most clients did not know anyone seeking to obtain fentanyl. Regardless, the high exposure underscores that naloxone training and distribution is needed. Copyright © 2017 Elsevier Inc. All rights reserved.

Free Software Development. 4. Client-Server Implementation of Bone Age Assessment Calculations

Directory of Open Access Journals (Sweden)

Sorana Daniela BOLBOACĂ

2003-03-01

Full Text Available In pediatrics, bone age also called skeletal maturity, an expression of biological maturity of a child, is an important quantitative measure for the clinical diagnosis of endocrinological problems and growth disorders. The present paper discusses a Java script implementation of Tanner-Whitehouse Method on computer, with complete graphical interface that include pictures and explanations for every bone. The program allows to select a stage (from a set of 7 or 8 stages for every bone (from a set of 20 bones, and also allow user to input some specific data such as natural age, sex, place of residence. Based on TW2 reported values, selected and input data, the program compute the bone age. Java script functions and objects were used in order to make an efficient and adaptive program. Note that in classic way, the program implementation it requires more than 160 groups of instructions only for user interface design. Using of dynamic creation of page, the program became smaller and efficient. The program was tested and put on a web server to serve for directly testing via http service and from where can also be download and runes from a personal computer without internet connection: http://vl.academicdirect.ro/medical_informatics/bone_age/v1.0/

Eliom: A core ML language for Tierless Web programming

OpenAIRE

Radanne , Gabriel; Vouillon , Jérôme; Balat , Vincent

2016-01-01

International audience; Eliom is a dialect of OCaml for Web programming in which server and client pieces of code can be mixed in the same file using syntactic annotations. This allows to build a whole application as a single distributed program, in which it is possible to define in a composable way reusable widgets with both server and client behaviors. Our language also enables simple and type-safe communication. Eliom matches the specificities of the Web by allowing the programmer to inter...

A gossip-based distributed social networking system

NARCIS (Netherlands)

Abbas, S.M.A.; Pouwelse, J.A.; Epema, D.H.J.; Sips, H.J.

2009-01-01

Social networking Web sites, which allow users to create identities and link them to friends who have also created identities, are highly popular. Systems such as Facebook and MySpace utilize a traditional client-server approach to achieve this, which means that all identities and their social links

PENGGUNAAN KONEKSI CORBA DENGAN PEMROGRAMAN MIDAS MULTI-TIER APPLICATION DALAM SISTEM RESERVASI HOTEL

Directory of Open Access Journals (Sweden)

Irwan Kristanto Julistiono

2001-01-01

Full Text Available This paper is made from a multi-tier system using corba technology for hotel reservation program for web browser and also client program. Client software is connected to application server with Corba Connection and client and application server connect to SQL server 7.0. via ODBC. The are 2 types of client: web client and delphi client. In making web browser client application, we use delphi activex from technology, in where in this system made like making the regular form, but it has shortage in integration with html language. Multi-pier application using corba system generally has another profit beside it could be developed, this system also stake with multi system database server, multi middle servers and multi client in which with these things all the system can system can be integrated. The weakness of this system is the complicated corba system, so it will be difficult to understand, while for multi-tier it self need a particular procedure to determine which server chossed by the client. Abstract in Bahasa Indonesia : Pada makalah ini dibuat suatu sistem multi-tier yang menggunakan teknologi CORBA untuk program reservasi hotel baik dengan web browser maupun program client. Perangkat lunak yang dipakai sebagai database server adalah SQL server 7.0. Program Client Delphi melalui Corba Connection akan dihubungkan ke Aplikasi server. Dan melalui ODBC Aplikasi Server akan dihubungkan ke SQL Server 7.0. Ada dua buah aplikasi client yaitu yang menggunakan lokal network dan yang menggunakan global network/web browser. Pada pembuatan aplikasi client untuk web browser. Digunakan teknologi activex form pada delphi dimana sistem ini dibuat seperti membuat form biasa, hanya saja memiliki kekurangan pada integrasi dengan bahasa html. Penggunaan sistem multi-tier dengan Corba ini secara umum memiliki keuntungan selain dapat dikembangkan lebih lanjut juga sistem ini dirancang dengan sistem multi database server, multi midle server, dan multi client dimana

Heterogeneous Data Fusion Method to Estimate Travel Time Distributions in Congested Road Networks

Directory of Open Access Journals (Sweden)

Chaoyang Shi

2017-12-01

Full Text Available Travel times in congested urban road networks are highly stochastic. Provision of travel time distribution information, including both mean and variance, can be very useful for travelers to make reliable path choice decisions to ensure higher probability of on-time arrival. To this end, a heterogeneous data fusion method is proposed to estimate travel time distributions by fusing heterogeneous data from point and interval detectors. In the proposed method, link travel time distributions are first estimated from point detector observations. The travel time distributions of links without point detectors are imputed based on their spatial correlations with links that have point detectors. The estimated link travel time distributions are then fused with path travel time distributions obtained from the interval detectors using Dempster-Shafer evidence theory. Based on fused path travel time distribution, an optimization technique is further introduced to update link travel time distributions and their spatial correlations. A case study was performed using real-world data from Hong Kong and showed that the proposed method obtained accurate and robust estimations of link and path travel time distributions in congested road networks.

How to ensure sustainable interoperability in heterogeneous distributed systems through architectural approach.

Science.gov (United States)

Pape-Haugaard, Louise; Frank, Lars

2011-01-01

A major obstacle in ensuring ubiquitous information is the utilization of heterogeneous systems in eHealth. The objective in this paper is to illustrate how an architecture for distributed eHealth databases can be designed without lacking the characteristic features of traditional sustainable databases. The approach is firstly to explain traditional architecture in central and homogeneous distributed database computing, followed by a possible approach to use an architectural framework to obtain sustainability across disparate systems i.e. heterogeneous databases, concluded with a discussion. It is seen that through a method of using relaxed ACID properties on a service-oriented architecture it is possible to achieve data consistency which is essential when ensuring sustainable interoperability.

Analysis of Multiserver Queueing System with Opportunistic Occupation and Reservation of Servers

Directory of Open Access Journals (Sweden)

Bin Sun

2014-01-01

Full Text Available We consider a multiserver queueing system with two input flows. Type-1 customers have preemptive priority and are lost during arrival only if all servers are occupied by type-1 customers. If all servers are occupied, but some provide service to type-2 customers, service of type-2 customer is terminated and type-1 customer occupies the server. If the number of busy servers is less than the threshold M during type-2 customer arrival epoch, this customer is accepted. Otherwise, it is lost or becomes a retrial customer. It will retry to obtain service. Type-2 customer whose service is terminated is lost or moves to the pool of retrial customers. The service time is exponentially distributed with the rate dependent on the customer’s type. Such queueing system is suitable for modeling cognitive radio. Type-1 customers are interpreted as requests generated by primary users. Type-2 customers are generated by secondary or cognitive users. The problem of optimal choice of the threshold M is the subject of this paper. Behavior of the system is described by the multidimensional Markov chain. Its generator, ergodicity condition, and stationary distribution are given. The system performance measures are obtained. The numerical results show the effectiveness of considered admission control.

Mastering Microsoft Exchange Server 2013

CERN Document Server

Elfassy, David

2013-01-01

The bestselling guide to Exchange Server, fully updated for the newest version Microsoft Exchange Server 2013 is touted as a solution for lowering the total cost of ownership, whether deployed on-premises or in the cloud. Like the earlier editions, this comprehensive guide covers every aspect of installing, configuring, and managing this multifaceted collaboration system. It offers Windows systems administrators and consultants a complete tutorial and reference, ideal for anyone installing Exchange Server for the first time or those migrating from an earlier Exchange Server version.Microsoft

Measuring participation of social-support clients: : validity and reliability of IPA-MO

NARCIS (Netherlands)

Berenschot, L.; Grift, Y.K.

2017-01-01

This study evaluates the reliability and validity of the Impact on Autonomy and Participation instrument (IPA) for heterogeneous populations of social support clients. Decentralisation of social support and accompanying budget cuts spurred interest in outcome-related payment systems to foster

Rancang Bangun Aplikasi Sistem Informasi Tanaman Obat Tradisional Berbasis Android

Directory of Open Access Journals (Sweden)

Ni Komang Surya Cahyani Putri

2016-01-01

Full Text Available Makalah ini membahas mengenai hubungan client-server yang terjadi pada Sistem Informasi Tanaman Obat Tradisional. Sistem informasi tanaman obat tradisional dibuat berbasis Android, untuk memudahkan masyarakat mengakses informasi dengan menggunakan mobile phone. aplikasi ini menggunakan database server, dimana hanya admin yang dapat mengakses dan melakukan edit, hapus dan update data pada database server. Aplikasi client dibangun pada perangkat mobile dengan sistem operasi Android. Aplikasi client hanya dapat mengakses informasi yang sudah disediakan oleh admin, dimana admin merupakan entitas yang bertugas untuk mengelola data master. Sisi server dibangun dengan basis web. Server memegang peranan khusus untuk mengelola data master pada basis data sistem. Hubungan client-server yang terjadi pada sistem menjaga data yang ada pada basis data sistem baik pada client maupun server tetap sinkron.   Kata kunci: Client-server, Tanaman Obat Tradisional, Sistem Informasi, Android.

Optimal routing of IP packets to multi-homed servers

International Nuclear Information System (INIS)

Swartz, K.L.

1992-08-01

Multi-homing, or direct attachment to multiple networks, offers both performance and availability benefits for important servers on busy networks. Exploiting these benefits to their fullest requires a modicum of routing knowledge in the clients. Careful policy control must also be reflected in the routing used within the network to make best use of specialized and often scarce resources. While relatively straightforward in theory, this problem becomes much more difficult to solve in a real network containing often intractable implementations from a variety of vendors. This paper presents an analysis of the problem and proposes a useful solution for a typical campus network. Application of this solution at the Stanford Linear Accelerator Center is studied and the problems and pitfalls encountered are discussed, as are the workarounds used to make the system work in the real world

Heterogeneity phantoms for visualization of 3D dose distributions by MRI-based polymer gel dosimetry

International Nuclear Information System (INIS)

Watanabe, Yoichi; Mooij, Rob; Mark Perera, G.; Maryanski, Marek J.

2004-01-01

Heterogeneity corrections in dose calculations are necessary for radiation therapy treatment plans. Dosimetric measurements of the heterogeneity effects are hampered if the detectors are large and their radiological characteristics are not equivalent to water. Gel dosimetry can solve these problems. Furthermore, it provides three-dimensional (3D) dose distributions. We used a cylindrical phantom filled with BANG-3 registered polymer gel to measure 3D dose distributions in heterogeneous media. The phantom has a cavity, in which water-equivalent or bone-like solid blocks can be inserted. The irradiated phantom was scanned with an magnetic resonance imaging (MRI) scanner. Dose distributions were obtained by calibrating the polymer gel for a relationship between the absorbed dose and the spin-spin relaxation rate of the magnetic resistance (MR) signal. To study dose distributions we had to analyze MR imaging artifacts. This was done in three ways: comparison of a measured dose distribution in a simulated homogeneous phantom with a reference dose distribution, comparison of a sagittally scanned image with a sagittal image reconstructed from axially scanned data, and coregistration of MR and computed-tomography images. We found that the MRI artifacts cause a geometrical distortion of less than 2 mm and less than 10% change in the dose around solid inserts. With these limitations in mind we could make some qualitative measurements. Particularly we observed clear differences between the measured dose distributions around an air-gap and around bone-like material for a 6 MV photon beam. In conclusion, the gel dosimetry has the potential to qualitatively characterize the dose distributions near heterogeneities in 3D

Mac OS X Lion Server For Dummies

CERN Document Server

Rizzo, John

2011-01-01

The perfect guide to help administrators set up Apple's Mac OS X Lion Server With the overwhelming popularity of the iPhone and iPad, more Macs are appearing in corporate settings. The newest version of Mac Server is the ideal way to administer a Mac network. This friendly guide explains to both Windows and Mac administrators how to set up and configure the server, including services such as iCal Server, Podcast Producer, Wiki Server, Spotlight Server, iChat Server, File Sharing, Mail Services, and support for iPhone and iPad. It explains how to secure, administer, and troubleshoot the networ

Open Polar Server (OPS—An Open Source Infrastructure for the Cryosphere Community

Directory of Open Access Journals (Sweden)

Weibo Liu

2016-03-01

Full Text Available The Center for Remote Sensing of Ice Sheets (CReSIS at the University of Kansas has collected approximately 1000 terabytes (TB of radar depth sounding data over the Arctic and Antarctic ice sheets since 1993 in an effort to map the thickness of the ice sheets and ultimately understand the impacts of climate change and sea level rise. In addition to data collection, the storage, management, and public distribution of the dataset are also primary roles of the CReSIS. The Open Polar Server (OPS project developed a free and open source infrastructure to store, manage, analyze, and distribute the data collected by CReSIS in an effort to replace its current data storage and distribution approach. The OPS infrastructure includes a spatial database management system (DBMS, map and web server, JavaScript geoportal, and MATLAB application programming interface (API for the inclusion of data created by the cryosphere community. Open source software including GeoServer, PostgreSQL, PostGIS, OpenLayers, ExtJS, GeoEXT and others are used to build a system that modernizes the CReSIS data distribution for the entire cryosphere community and creates a flexible platform for future development. Usability analysis demonstrates the OPS infrastructure provides an improved end user experience. In addition, interpolating glacier topography is provided as an application example of the system.

Heterogeneous High Throughput Scientific Computing with APM X-Gene and Intel Xeon Phi

CERN Document Server

Abdurachmanov, David; Elmer, Peter; Eulisse, Giulio; Knight, Robert; Muzaffar, Shahzad

2014-01-01

Electrical power requirements will be a constraint on the future growth of Distributed High Throughput Computing (DHTC) as used by High Energy Physics. Performance-per-watt is a critical metric for the evaluation of computer architectures for cost- efficient computing. Additionally, future performance growth will come from heterogeneous, many-core, and high computing density platforms with specialized processors. In this paper, we examine the Intel Xeon Phi Many Integrated Cores (MIC) co-processor and Applied Micro X-Gene ARMv8 64-bit low-power server system-on-a-chip (SoC) solutions for scientific computing applications. We report our experience on software porting, performance and energy efficiency and evaluate the potential for use of such technologies in the context of distributed computing systems such as the Worldwide LHC Computing Grid (WLCG).

Heterogeneous High Throughput Scientific Computing with APM X-Gene and Intel Xeon Phi

Science.gov (United States)

Abdurachmanov, David; Bockelman, Brian; Elmer, Peter; Eulisse, Giulio; Knight, Robert; Muzaffar, Shahzad

2015-05-01

Electrical power requirements will be a constraint on the future growth of Distributed High Throughput Computing (DHTC) as used by High Energy Physics. Performance-per-watt is a critical metric for the evaluation of computer architectures for cost- efficient computing. Additionally, future performance growth will come from heterogeneous, many-core, and high computing density platforms with specialized processors. In this paper, we examine the Intel Xeon Phi Many Integrated Cores (MIC) co-processor and Applied Micro X-Gene ARMv8 64-bit low-power server system-on-a-chip (SoC) solutions for scientific computing applications. We report our experience on software porting, performance and energy efficiency and evaluate the potential for use of such technologies in the context of distributed computing systems such as the Worldwide LHC Computing Grid (WLCG).

Heterogeneous High Throughput Scientific Computing with APM X-Gene and Intel Xeon Phi

International Nuclear Information System (INIS)

Abdurachmanov, David; Bockelman, Brian; Elmer, Peter; Eulisse, Giulio; Muzaffar, Shahzad; Knight, Robert

2015-01-01

Electrical power requirements will be a constraint on the future growth of Distributed High Throughput Computing (DHTC) as used by High Energy Physics. Performance-per-watt is a critical metric for the evaluation of computer architectures for cost- efficient computing. Additionally, future performance growth will come from heterogeneous, many-core, and high computing density platforms with specialized processors. In this paper, we examine the Intel Xeon Phi Many Integrated Cores (MIC) co-processor and Applied Micro X-Gene ARMv8 64-bit low-power server system-on-a-chip (SoC) solutions for scientific computing applications. We report our experience on software porting, performance and energy efficiency and evaluate the potential for use of such technologies in the context of distributed computing systems such as the Worldwide LHC Computing Grid (WLCG). (paper)

Learning Zimbra Server essentials

CERN Document Server

Kouka, Abdelmonam

2013-01-01

A standard tutorial approach which will guide the readers on all of the intricacies of the Zimbra Server.If you are any kind of Zimbra user, this book will be useful for you, from newbies to experts who would like to learn how to setup a Zimbra server. If you are an IT administrator or consultant who is exploring the idea of adopting, or have already adopted Zimbra as your mail server, then this book is for you. No prior knowledge of Zimbra is required.

Sexually transmitted infections among heterosexual male clients of female sex workers in China: a systematic review and meta-analysis.

Directory of Open Access Journals (Sweden)

Megan M McLaughlin

Full Text Available Female sex workers have been the target of numerous sexually transmitted infection (STI prevention strategies in China, but their male clients have attracted considerably less public health attention and resources. We sought to systematically assess the prevalence of HIV, syphilis, gonorrhea, and chlamydia among heterosexual male clients of female sex workers in China.Original research manuscripts were identified by searching Chinese and English language databases, and 37 studies analyzing 26,552 male clients were included in the review. Client STI prevalence across studies was heterogeneous. Pooled prevalence estimates and 95% confidence intervals were 0.68% (0.36-1.28% for HIV, 2.91% (2.17-3.89% for syphilis, 2.16% (1.46-3.17% for gonorrhea, and 8.01% (4.94-12.72% for chlamydia.The pooled prevalence estimates of HIV, syphilis, gonorrhea, and chlamydia among clients in this review exceed the prevalences previously reported among population-representative samples and low-risk groups in China. However, heterogeneity across studies and sampling limitations prevent definitive conclusions about how the prevalence of STIs in this population compares to the general population. These findings suggest a need for greater attention to clients' sexual risk and disease prevalence in China's STI research agenda in order to inform effective prevention policies.

A study on client needs regarding FDG-PET for cancer screening

International Nuclear Information System (INIS)

Yamane, Tomohiko; Yoshiya, Kazuhiko; Nagata, Takeshi; Ito, Shinichi; Ito, Satoshi; Mezaki, Yukio; Uchida, Hideo

2006-01-01

We researched client needs regarding FDG-PET for cancer screening. The study included 1,527 individuals who underwent FDG-PET for cancer screening at our hospital. An interview sheet was distributed after injecting FDG. Clients listed the organs that required examination and the symptoms causing them anxiety. Results indicated that 9.8% of the clients listed organs for which FDG-PET would not be useful in detecting cancer. This study suggested that there exists a gap between client needs and FDG-PET utility; hence we need improved methods of providing correct information to clients. (author)

Replikasi Unidirectional pada Heterogen Database

Directory of Open Access Journals (Sweden)

Hendro Nindito

2013-12-01

Full Text Available The use of diverse database technology in enterprise today can not be avoided. Thus, technology is needed to generate information in real time. The purpose of this research is to discuss a database replication technology that can be applied in heterogeneous database environments. In this study we use Windows-based MS SQL Server database to Linux-based Oracle database as the goal. The research method used is prototyping where development can be done quickly and testing of working models of the interaction process is done through repeated. From this research it is obtained that the database replication technolgy using Oracle Golden Gate can be applied in heterogeneous environments in real time as well.

Tierless Web programming in ML

OpenAIRE

Radanne , Gabriel

2017-01-01

Eliom is a dialect of OCaml for Web programming in which server and client pieces of code can be mixed in the same file using syntactic annotations. This allows to build a whole application as a single distributed program, in which it is possible to define in a composable way reusable widgets with both server and client behaviors. Eliom is type-safe, as it ensures that communications are well-behaved through novel language constructs that match the specificity of Web programming. Eliom is als...

Heterogeneous distribution of prokaryotes and viruses at the microscale in a tidal sediment

DEFF Research Database (Denmark)

Carreira, Cátia; Larsen, Morten; Glud, Ronnie

2013-01-01

In this study we show for the first time the microscale (mm) 2- and 3-dimensional spatial distribution and abundance of prokaryotes, viruses, and oxygen in a tidal sediment. Prokaryotes and viruses were highly heterogeneously distributed with patches of elevated abundances surrounded by areas of ...

Microsoft Windows Server Administration Essentials

CERN Document Server

Carpenter, Tom

2011-01-01

The core concepts and technologies you need to administer a Windows Server OS Administering a Windows operating system (OS) can be a difficult topic to grasp, particularly if you are new to the field of IT. This full-color resource serves as an approachable introduction to understanding how to install a server, the various roles of a server, and how server performance and maintenance impacts a network. With a special focus placed on the new Microsoft Technology Associate (MTA) certificate, the straightforward, easy-to-understand tone is ideal for anyone new to computer administration looking t

GeoServer: il server geospaziale Open Source novità della nuova versione 2.3.0

Directory of Open Access Journals (Sweden)

Simone Giannecchini

2013-04-01

Full Text Available GeoServer è un server geospaziale Open Source sviluppato con tecnologia Java Enterprise per la gestione e l’editing di dati geospaziali secondo gli standard OGC e ISO Technical Committee 211. Esso fornisce le funzionalità di base per creareinfrastrutture spaziali di dati (SDI ed è progettato per essere interoperabile potendo pubblicare dati provenienti da ogni tipo di fonte spaziale utilizzando standard aperti.Open Source GeoSpatial server developed with Java Enterprise technology for managing, sharing and editing geospatial data according to the OGC and ISO TC 211 standards. GeoServer provides the basic functionalities to create spatial data infrastructures (SDI.GeoServer is designed for interoperability, it publishes data from any major spatial data source using open standards: it is the reference implementation of the Open Geospatial Consortium (OGC Web Feature Service (WFS and Web Coverage Service (WCS standards, as well as a highperformance certified compliant Web Map Service (WMS. GeoServer forms a core component of the Geospatial Web.

Distributed applications monitoring at system and network level

CERN Document Server

Aderholz, Michael; Augé, E; Bagliesi, G; Banistoni, G; Barone, L; Boschini, M; Brunengo, A; Bunn, J J; Butler, J; Campanella, M; Capiluppi, P; D'Amato, M; Darneri, M; Di Mattia, A; Dorokhov, A E; Gagliardi, F; Gaines, I; Gasparini, U; Ghiselli, A; Gordon, J; Grandi, C; Gálvez, P; Harris, F; Holtman, K; Karimäki, V; Karita, Y; Klem, J T; Legrand, I; Leltchouk, M; Linglin, D; Lubrano, P; Luminari, L; McArthur, I C; Michelotto, M; Morita, Y; Nazarenko, A; Newman, H; O'Dell, Vivian; O'Neale, S W; Osculati, B; Pepé, M; Perini, L; Pinfold, James L; Pordes, R; Prelz, F; Putzer, A; Resconi, S; Robertson, L; Rolli, S; Sasaki, T; Sato, H; Schaffer, R D; Schalk, T L; Servoli, L; Sgaravatto, M; Shiers, J; Silvestris, L; Siroli, G P; Sliwa, K; Smith, T; Somigliana, R; Stanescu, C; Stockinger, H E; Ugolotti, D; Valente, E; Vistoli, C; Wilkinson, R P; Willers, Ian Malcolm; Williams, D O

2001-01-01

Most distributed applications are based on architectural models that do not involve real-time knowledge of network status and of their network usage. Moreover the new "network aware" architectures are still under development and their design is not yet complete. We considered, as a use case, an application using ODBMS (Objectivity /DB) for the distributed analysis of experimental data. The dynamic usage of system and network resources at host and application levels has been measured in different client/server configurations, and on several LAN and WAN layouts. The aim was to study the application efficiency and behavior versus the network characteristics and conditions. The most interesting results of the LAN and WAN tests are described. System bottlenecks and limitations have been identified, and efficient working conditions in the different scenarios have been defined. The behavior observed when moving away from the optimal working conditions is also described.

DATABASE REPLICATION IN HETEROGENOUS PLATFORM

OpenAIRE

Hendro Nindito; Evaristus Didik Madyatmadja; Albert Verasius Dian Sano

2014-01-01

The application of diverse database technologies in enterprises today is increasingly a common practice. To provide high availability and survavibality of real-time information, a database replication technology that has capability to replicate databases under heterogenous platforms is required. The purpose of this research is to find the technology with such capability. In this research, the data source is stored in MSSQL database server running on Windows. The data will be replicated to MyS...

Professional Microsoft SQL Server 2012 Administration

CERN Document Server

Jorgensen, Adam; LoForte, Ross; Knight, Brian

2012-01-01

An essential how-to guide for experienced DBAs on the most significant product release since 2005! Microsoft SQL Server 2012 will have major changes throughout the SQL Server and will impact how DBAs administer the database. With this book, a team of well-known SQL Server experts introduces the many new features of the most recent version of SQL Server and deciphers how these changes will affect the methods that administrators have been using for years. Loaded with unique tips, tricks, and workarounds for handling the most difficult SQL Server admin issues, this how-to guide deciphers topics s

Management of Distributed and Extendible Heterogeneous Radio Architectures

DEFF Research Database (Denmark)

Ramkumar, Venkata; Mihovska, Albena D.; Prasad, Neeli R.

2009-01-01

Wireless communication systems are dynamic by nature, which comes from several factors, namely: radio propagation impairments, traffic changes, interference conditions, user mobility, etc. In a heterogeneous environment, , the dynamic network behavior calls for a dynamic management of the radio...... resources; a process that associates a large number of parameters and quality/performance indicators that need to be set, measured, analyzed, and optimized. Radio-over-fiber (RoF) technology involves the use of optical fiber links to distribute radio frequency (RF) signals from a central location to remote...

CT Identification and Fractal Characterization of 3-D Propagation and Distribution of Hydrofracturing Cracks in Low-Permeability Heterogeneous Rocks

Science.gov (United States)

Liu, Peng; Ju, Yang; Gao, Feng; Ranjith, Pathegama G.; Zhang, Qianbing

2018-03-01

Understanding and characterization of the three-dimensional (3-D) propagation and distribution of hydrofracturing cracks in heterogeneous rock are key for enhancing the stimulation of low-permeability petroleum reservoirs. In this study, we investigated the propagation and distribution characteristics of hydrofracturing cracks, by conducting true triaxial hydrofracturing tests and computed tomography on artificial heterogeneous rock specimens. Silica sand, Portland cement, and aedelforsite were mixed to create artificial heterogeneous rock specimens using the data of mineral compositions, coarse gravel distribution, and mechanical properties that were measured from the natural heterogeneous glutenite cores. To probe the effects of material heterogeneity on hydrofracturing cracks, the artificial homogenous specimens were created using the identical matrix compositions of the heterogeneous rock specimens and then fractured for comparison. The effects of horizontal geostress ratio on the 3-D growth and distribution of cracks during hydrofracturing were examined. A fractal-based method was proposed to characterize the complexity of fractures and the efficiency of hydrofracturing stimulation of heterogeneous media. The material heterogeneity and horizontal geostress ratio were found to significantly influence the 3-D morphology, growth, and distribution of hydrofracturing cracks. A horizontal geostress ratio of 1.7 appears to be the upper limit for the occurrence of multiple cracks, and higher ratios cause a single crack perpendicular to the minimum horizontal geostress component. The fracturing efficiency is associated with not only the fractured volume but also the complexity of the crack network.

The EarthServer Federation: State, Role, and Contribution to GEOSS

Science.gov (United States)

Merticariu, Vlad; Baumann, Peter

2016-04-01

The intercontinental EarthServer initiative has established a European datacube platform with proven scalability: known databases exceed 100 TB, and single queries have been split across more than 1,000 cloud nodes. Its service interface being rigorously based on the OGC "Big Geo Data" standards, Web Coverage Service (WCS) and Web Coverage Processing Service (WCPS), a series of clients can dock into the services, ranging from open-source OpenLayers and QGIS over open-source NASA WorldWind to proprietary ESRI ArcGIS. Datacube fusion in a "mix and match" style is supported by the platform technolgy, the rasdaman Array Database System, which transparently federates queries so that users simply approach any node of the federation to access any data item, internally optimized for minimal data transfer. Notably, rasdaman is part of GEOSS GCI. NASA is contributing its Web WorldWind virtual globe for user-friendly data extraction, navigation, and analysis. Integrated datacube / metadata queries are contributed by CITE. Current federation members include ESA (managed by MEEO sr.l.), Plymouth Marine Laboratory (PML), the European Centre for Medium-Range Weather Forecast (ECMWF), Australia's National Computational Infrastructure, and Jacobs University (adding in Planetary Science). Further data centers have expressed interest in joining. We present the EarthServer approach, discuss its underlying technology, and illustrate the contribution this datacube platform can make to GEOSS.

Effects of Fiber Type and Size on the Heterogeneity of Oxygen Distribution in Exercising Skeletal Muscle

Science.gov (United States)

Liu, Gang; Mac Gabhann, Feilim; Popel, Aleksander S.

2012-01-01

The process of oxygen delivery from capillary to muscle fiber is essential for a tissue with variable oxygen demand, such as skeletal muscle. Oxygen distribution in exercising skeletal muscle is regulated by convective oxygen transport in the blood vessels, oxygen diffusion and consumption in the tissue. Spatial heterogeneities in oxygen supply, such as microvascular architecture and hemodynamic variables, had been observed experimentally and their marked effects on oxygen exchange had been confirmed using mathematical models. In this study, we investigate the effects of heterogeneities in oxygen demand on tissue oxygenation distribution using a multiscale oxygen transport model. Muscles are composed of different ratios of the various fiber types. Each fiber type has characteristic values of several parameters, including fiber size, oxygen consumption, myoglobin concentration, and oxygen diffusivity. Using experimentally measured parameters for different fiber types and applying them to the rat extensor digitorum longus muscle, we evaluated the effects of heterogeneous fiber size and fiber type properties on the oxygen distribution profile. Our simulation results suggest a marked increase in spatial heterogeneity of oxygen due to fiber size distribution in a mixed muscle. Our simulations also suggest that the combined effects of fiber type properties, except size, do not contribute significantly to the tissue oxygen spatial heterogeneity. However, the incorporation of the difference in oxygen consumption rates of different fiber types alone causes higher oxygen heterogeneity compared to control cases with uniform fiber properties. In contrast, incorporating variation in other fiber type-specific properties, such as myoglobin concentration, causes little change in spatial tissue oxygenation profiles. PMID:23028531

Bringing it All Together: NODC's Geoportal Server as an Integration Tool for Interoperable Data Services

Science.gov (United States)

Casey, K. S.; Li, Y.

2011-12-01

to utilize the Geoportal Server as an integrator of services. Scientific and other users can now come to the NODC Geoportal Server, or search it directly from their client applications, and not only find archived data sets and products but also all of the available interoperable access, subsetting, reformatting, and visualization services available for their search results. This framework will be presented with an emphasis on how it both simplifies the discovery and access process for the user and exposes the rich complexity of services available for any given data set in meaningful and accessible ways.

Next generation tools for genomic data generation, distribution, and visualization.

Science.gov (United States)

Nix, David A; Di Sera, Tonya L; Dalley, Brian K; Milash, Brett A; Cundick, Robert M; Quinn, Kevin S; Courdy, Samir J

2010-09-09

With the rapidly falling cost and availability of high throughput sequencing and microarray technologies, the bottleneck for effectively using genomic analysis in the laboratory and clinic is shifting to one of effectively managing, analyzing, and sharing genomic data. Here we present three open-source, platform independent, software tools for generating, analyzing, distributing, and visualizing genomic data. These include a next generation sequencing/microarray LIMS and analysis project center (GNomEx); an application for annotating and programmatically distributing genomic data using the community vetted DAS/2 data exchange protocol (GenoPub); and a standalone Java Swing application (GWrap) that makes cutting edge command line analysis tools available to those who prefer graphical user interfaces. Both GNomEx and GenoPub use the rich client Flex/Flash web browser interface to interact with Java classes and a relational database on a remote server. Both employ a public-private user-group security model enabling controlled distribution of patient and unpublished data alongside public resources. As such, they function as genomic data repositories that can be accessed manually or programmatically through DAS/2-enabled client applications such as the Integrated Genome Browser. These tools have gained wide use in our core facilities, research laboratories and clinics and are freely available for non-profit use. See http://sourceforge.net/projects/gnomex/, http://sourceforge.net/projects/genoviz/, and http://sourceforge.net/projects/useq.

GSKY: A scalable distributed geospatial data server on the cloud

Science.gov (United States)

Rozas Larraondo, Pablo; Pringle, Sean; Antony, Joseph; Evans, Ben

2017-04-01

Earth systems, environmental and geophysical datasets are an extremely valuable sources of information about the state and evolution of the Earth. Being able to combine information coming from different geospatial collections is in increasing demand by the scientific community, and requires managing and manipulating data with different formats and performing operations such as map reprojections, resampling and other transformations. Due to the large data volume inherent in these collections, storing multiple copies of them is unfeasible and so such data manipulation must be performed on-the-fly using efficient, high performance techniques. Ideally this should be performed using a trusted data service and common system libraries to ensure wide use and reproducibility. Recent developments in distributed computing based on dynamic access to significant cloud infrastructure opens the door for such new ways of processing geospatial data on demand. The National Computational Infrastructure (NCI), hosted at the Australian National University (ANU), has over 10 Petabytes of nationally significant research data collections. Some of these collections, which comprise a variety of observed and modelled geospatial data, are now made available via a highly distributed geospatial data server, called GSKY (pronounced [jee-skee]). GSKY supports on demand processing of large geospatial data products such as satellite earth observation data as well as numerical weather products, allowing interactive exploration and analysis of the data. It dynamically and efficiently distributes the required computations among cloud nodes providing a scalable analysis framework that can adapt to serve large number of concurrent users. Typical geospatial workflows handling different file formats and data types, or blending data in different coordinate projections and spatio-temporal resolutions, is handled transparently by GSKY. This is achieved by decoupling the data ingestion and indexing process as

A k-out-of-n reliability system with an unreliable server and phase type repairs and services: the (N,T policy

Directory of Open Access Journals (Sweden)

Srinivas R. Chakravarthy

2001-01-01

Full Text Available In this paper we study a k-out-of-n reliability system in which a single unreliable server maintains n identical components. The reliability system is studied under the (N,T policy. An idle server takes a vacation for a random amount of time T and then attends to any failed component waiting in line upon completion of the vacation. The vacationing server is recalled instantaneously upon the failure of the Nth component. The failure times of the components are assumed to follow an exponential distribution. The server is subject to failure with failure times exponentially distributed. Repair times of the component, fixing times of the server, and vacationing times of the server are assumed to be of phase type. Using matrix-analytic methods we perform steady state analysis of this model. Time spent by a failed component in service, total time in the repair facility, vacation time of the server, non-vacation time of the server, and time until failure of the system are all shown to be of phase type. Several performance measures are evaluated. Illustrative numerical examples are presented.

Web tools for effective retrieval, visualization, and evaluation of cardiology medical images and records

Science.gov (United States)

Masseroli, Marco; Pinciroli, Francesco

2000-12-01

To provide easy retrieval, integration and evaluation of multimodal cardiology images and data in a web browser environment, distributed application technologies and java programming were used to implement a client-server architecture based on software agents. The server side manages secure connections and queries to heterogeneous remote databases and file systems containing patient personal and clinical data. The client side is a Java applet running in a web browser and providing a friendly medical user interface to perform queries on patient and medical test dat and integrate and visualize properly the various query results. A set of tools based on Java Advanced Imaging API enables to process and analyze the retrieved cardiology images, and quantify their features in different regions of interest. The platform-independence Java technology makes the developed prototype easy to be managed in a centralized form and provided in each site where an intranet or internet connection can be located. Giving the healthcare providers effective tools for querying, visualizing and evaluating comprehensively cardiology medical images and records in all locations where they can need them- i.e. emergency, operating theaters, ward, or even outpatient clinics- the developed prototype represents an important aid in providing more efficient diagnoses and medical treatments.

Sensors in Distributed Mixed Reality Environments

Directory of Open Access Journals (Sweden)

Felix Hamza-Lup

2005-04-01

Full Text Available A distributed mixed-reality (MR or virtual reality (VR environment implies the cooperative engagement of a set of software and hardware resources. With the advances in sensors and computer networks we have seen an increase in the number of potential MR/VR applications that require large amounts of information from the real world collected through sensors (e.g. position and orientation tracking sensors. These sensors collect data from the real environment in real-time at different locations and a distributed environment connecting them must assure data distribution among collaborative sites at interactive speeds. With the advances in sensor technology, we envision that in future systems a significant amount of data will be collected from sensors and devices attached to the participating nodes This paper proposes a new architecture for sensor based interactive distributed MR/VR environments that falls in-between the atomistic peer-to-peer model and the traditional client-server model. Each node is autonomous and fully manages its resources and connectivity. The dynamic behavior of the nodes is dictated by the human participants that manipulate the sensors attached to these nodes.

Synchronization resources in heterogeneous environments: Time-sharing, real-time and Java

Energy Technology Data Exchange (ETDEWEB)

Pereira, A. [Asociacion EURATOM/CIEMAT para Fusion, CIEMAT Edificio 66, Avda. Complutense, 22, 28040 Madrid (Spain)]. E-mail: augusto.pereira@ciemat.es; Vega, J. [Asociacion EURATOM/CIEMAT para Fusion, CIEMAT Edificio 66, Avda. Complutense, 22, 28040 Madrid (Spain); Pacios, L. [Asociacion EURATOM/CIEMAT para Fusion, CIEMAT Edificio 66, Avda. Complutense, 22, 28040 Madrid (Spain); Sanchez, E. [Asociacion EURATOM/CIEMAT para Fusion, CIEMAT Edificio 66, Avda. Complutense, 22, 28040 Madrid (Spain); Portas, A. [Asociacion EURATOM/CIEMAT para Fusion, CIEMAT Edificio 66, Avda. Complutense, 22, 28040 Madrid (Spain)

2006-07-15

The asynchronous event distribution system (AEDS) was built to provide synchronization resources within the TJ-II local area network. It is a software system developed to add 'soft synchronization' capabilities to the TJ-II data acquisition, control and analysis environments. 'Soft synchronization' signifies that AEDS is not a real-time system. In fact, AEDS is based on TCP/IP over ETHERNET networks. However, its response time is adequate for practical purposes when synchronization requirements can support some delay between event dispatch and message reception. Event broadcasters (or synchronization servers in AEDS terminology) are Windows computers. Destination computers (or synchronization clients) were also Windows machines in the first version of AEDS. However, this fact imposed a very important limitation on synchronization capabilities. To overcome this situation, synchronization clients for different environments have been added to AEDS: for time-sharing operating systems (Unix and Linux), real-time operating systems (OS-9 and VxWorks) and Java applications. These environments have different synchronization primitives, requiring different approaches to provide the required uniform functionality. This has been achieved with POSIX thread library synchronization primitives (mutex and condition variables) on Unix/Linux systems, IPC mechanisms for concurrent processes on OS-9 and VxWorks real-time operating systems, and 'synchronized-wait/notify' primitives on Java virtual machines.

On distributed key distribution centers and unconditionally secure proactive verifiable secret sharing schemes based on general access structure

NARCIS (Netherlands)

Nikov, V.S.; Nikova, S.I.; Preneel, B.; Vandewalle, J.; Menezes, A.; Sarkar, P.

2002-01-01

A Key Distribution Center of a network is a server enabling private communications within groups of users. A Distributed Key Distribution Center is a set of servers that jointly realizes a Key Distribution Center. In this paper we build a robust Distributed Key Distribution Center Scheme secure

The Network Configuration of an Object Relational Database Management System

Science.gov (United States)

Diaz, Philip; Harris, W. C.

2000-01-01

The networking and implementation of the Oracle Database Management System (ODBMS) requires developers to have knowledge of the UNIX operating system as well as all the features of the Oracle Server. The server is an object relational database management system (DBMS). By using distributed processing, processes are split up between the database server and client application programs. The DBMS handles all the responsibilities of the server. The workstations running the database application concentrate on the interpretation and display of data.

Effects of species biological traits and environmental heterogeneity on simulated tree species distribution shifts under climate change.

Science.gov (United States)

Wang, Wen J; He, Hong S; Thompson, Frank R; Spetich, Martin A; Fraser, Jacob S

2018-09-01

Demographic processes (fecundity, dispersal, colonization, growth, and mortality) and their interactions with environmental changes are not well represented in current climate-distribution models (e.g., niche and biophysical process models) and constitute a large uncertainty in projections of future tree species distribution shifts. We investigate how species biological traits and environmental heterogeneity affect species distribution shifts. We used a species-specific, spatially explicit forest dynamic model LANDIS PRO, which incorporates site-scale tree species demography and competition, landscape-scale dispersal and disturbances, and regional-scale abiotic controls, to simulate the distribution shifts of four representative tree species with distinct biological traits in the central hardwood forest region of United States. Our results suggested that biological traits (e.g., dispersal capacity, maturation age) were important for determining tree species distribution shifts. Environmental heterogeneity, on average, reduced shift rates by 8% compared to perfect environmental conditions. The average distribution shift rates ranged from 24 to 200myear -1 under climate change scenarios, implying that many tree species may not able to keep up with climate change because of limited dispersal capacity, long generation time, and environmental heterogeneity. We suggest that climate-distribution models should include species demographic processes (e.g., fecundity, dispersal, colonization), biological traits (e.g., dispersal capacity, maturation age), and environmental heterogeneity (e.g., habitat fragmentation) to improve future predictions of species distribution shifts in response to changing climates. Copyright © 2018 Elsevier B.V. All rights reserved.

Control server for the PS orbit acquisition system Status 2009

CERN Document Server

Bart-Pedersen, S; CERN. Geneva. BE Department

2009-01-01

CERN’s Proton Synchrotron (CPS) has been fitted with a new Trajectory Measurement System (TMS). Analogue signals from forty Beam Position Monitors (BPM) are digitized at 125 MS/s, and then further treated in the digital domain to derive positions of all individual particle bunches on the fly. Large FPGAs are used to handle the digital processing. The system fits in fourteen plug-in modules distributed over three half-width cPCI crates that store data in circular buffers. They are connected to a Linux computer by means of a private Gigabit Ethernet segment. Dedicated server software, running under Linux, knits the system into a coherent whole [1]. The corresponding low-level software using FESA (BPMOPS class) was implemented while respecting the standard interface for beam position measurements. The BPMOPS server publishes values on request after data extraction and conversion from the TMS server. This software is running on a VME Lynx-OS platform and through dedicated electronics it can therefore control th...

Server for experimental data from LHD

International Nuclear Information System (INIS)

Emoto, M.; Ohdachi, S.; Watanabe, K.; Sudo, S.; Nagayama, Y.

2006-01-01

In order to unify various types of data, the Kaiseki Server was developed. This server provides physical experimental data of large helical device (LHD) experiments. Many types of data acquisition systems currently exist in operation, and they produce files of various formats. Therefore, it has been difficult to analyze different types of acquisition data at the same time because the data of each system should be read in a particular manner. To facilitate the usage of this data by researchers, the authors have developed a new server system, which provides a unified data format and a unique data retrieval interface. Although the Kaiseki Server satisfied the initial demand, new requests arose from researchers, one of which was the remote usage of the server. The current system cannot be used remotely because of security issues. Another request was group ownership, i.e., users belonging to the same group should have equal access to data. To satisfy these demands, the authors modified the server. However, since other requests may arise in the future, the new system must be flexible so that it can satisfy future demands. Therefore, the authors decided to develop a new server using a three-tier structure

Windows Server 2012 R2 administrator cookbook

CERN Document Server

Krause, Jordan

2015-01-01

This book is intended for system administrators and IT professionals with experience in Windows Server 2008 or Windows Server 2012 environments who are looking to acquire the skills and knowledge necessary to manage and maintain the core infrastructure required for a Windows Server 2012 and Windows Server 2012 R2 environment.

NRSAS: Nuclear Receptor Structure Analysis Servers.

NARCIS (Netherlands)

Bettler, E.J.M.; Krause, R.; Horn, F.; Vriend, G.

2003-01-01

We present a coherent series of servers that can perform a large number of structure analyses on nuclear hormone receptors. These servers are part of the NucleaRDB project, which provides a powerful information system for nuclear hormone receptors. The computations performed by the servers include

Long-term spatial heterogeneity in mallard distribution in the Prairie pothole region

Science.gov (United States)

Janke, Adam K.; Anteau, Michael J.; Stafford, Joshua D.

2017-01-01

The Prairie Pothole Region (PPR) of north-central United States and south-central Canada supports greater than half of all breeding mallards (Anas platyrhynchos) annually counted in North America and is the focus of widespread conservation and research efforts. Allocation of conservation resources for this socioeconomically important population would benefit from an understanding of the nature of spatiotemporal variation in distribution of breeding mallards throughout the 850,000 km2 landscape. We used mallard counts from the Waterfowl Breeding Population and Habitat Survey to test for spatial heterogeneity and identify high- and low-abundance regions of breeding mallards over a 50-year time series. We found strong annual spatial heterogeneity in all years: 90% of mallards counted annually were on an average of only 15% of surveyed segments. Using a local indicator of spatial autocorrelation, we found a relatively static distribution of low-count clusters in northern Montana, USA, and southern Alberta, Canada, and a dynamic distribution of high-count clusters throughout the study period. Distribution of high-count clusters shifted southeast from northwestern portions of the PPR in Alberta and western Saskatchewan, Canada, to North and South Dakota, USA, during the latter half of the study period. This spatial redistribution of core mallard breeding populations was likely driven by interactions between environmental variation that created favorable hydrological conditions for wetlands in the eastern PPR and dynamic land-use patterns related to upland cropping practices and government land-retirement programs. Our results highlight an opportunity for prioritizing relatively small regions within the PPR for allocation of wetland and grassland conservation for mallard populations. However, the extensive spatial heterogeneity in core distributions over our study period suggests such spatial prioritization will have to overcome challenges presented by dynamic land

An M[X]/G(a,b/1 Queueing System with Breakdown and Repair, Stand-By Server, Multiple Vacation and Control Policy on Request for Re-Service

Directory of Open Access Journals (Sweden)

G. Ayyappan

2018-06-01

Full Text Available In this paper, we discuss a non-Markovian batch arrival general bulk service single-server queueing system with server breakdown and repair, a stand-by server, multiple vacation and re-service. The main server’s regular service time, re-service time, vacation time and stand-by server’s service time are followed by general distributions and breakdown and repair times of the main server with exponential distributions. There is a stand-by server which is employed during the period in which the regular server remains under repair. The probability generating function of the queue size at an arbitrary time and some performance measures of the system are derived. Extensive numerical results are also illustrated.

Scalable Multi-Platform Distribution of Spatial 3d Contents

Science.gov (United States)

Klimke, J.; Hagedorn, B.; Döllner, J.

2013-09-01

Virtual 3D city models provide powerful user interfaces for communication of 2D and 3D geoinformation. Providing high quality visualization of massive 3D geoinformation in a scalable, fast, and cost efficient manner is still a challenging task. Especially for mobile and web-based system environments, software and hardware configurations of target systems differ significantly. This makes it hard to provide fast, visually appealing renderings of 3D data throughout a variety of platforms and devices. Current mobile or web-based solutions for 3D visualization usually require raw 3D scene data such as triangle meshes together with textures delivered from server to client, what makes them strongly limited in terms of size and complexity of the models they can handle. In this paper, we introduce a new approach for provisioning of massive, virtual 3D city models on different platforms namely web browsers, smartphones or tablets, by means of an interactive map assembled from artificial oblique image tiles. The key concept is to synthesize such images of a virtual 3D city model by a 3D rendering service in a preprocessing step. This service encapsulates model handling and 3D rendering techniques for high quality visualization of massive 3D models. By generating image tiles using this service, the 3D rendering process is shifted from the client side, which provides major advantages: (a) The complexity of the 3D city model data is decoupled from data transfer complexity (b) the implementation of client applications is simplified significantly as 3D rendering is encapsulated on server side (c) 3D city models can be easily deployed for and used by a large number of concurrent users, leading to a high degree of scalability of the overall approach. All core 3D rendering techniques are performed on a dedicated 3D rendering server, and thin-client applications can be compactly implemented for various devices and platforms.

Distributed Multi-interface Catalogue for Geospatial Data

Science.gov (United States)

Nativi, S.; Bigagli, L.; Mazzetti, P.; Mattia, U.; Boldrini, E.

2007-12-01

inventory systems. Prominent features include: 1)Support to distributed queries over a hierarchical data model, supporting incremental queries (i.e. query over collections, to be subsequently refined) and opaque/translucent chaining; 2)Support to several client protocols, through a compound front-end interface module. This allows to accommodate a (growing) number of cataloguing standards, or profiles thereof, including the OGC CSW interface, ebRIM Application Profile (for Core ISO Metadata and other data models), and the ISO Application Profile. The presented catalog clearinghouse supports both the opaque and translucent pattern for service chaining. In fact, the clearinghouse catalog may be configured either to completely hide the underlying federated services or to provide clients with services information. In both cases, the clearinghouse solution presents a higher level interface (i.e. OGC CSW) which harmonizes multiple lower level services (e.g. OGC CSW, WMS and WCS, THREDDS, etc.), and handles all control and interaction with them. In the translucent case, client has the option to directly access the lower level services (e.g. to improve performances). In the GEOSS context, the solution has been experimented both as a stand-alone user application and as a service framework. The first scenario allows a user to download a multi-platform client software and query a federation of cataloguing systems, that he can customize at will. The second scenario support server-side deployment and can be flexibly adapted to several use-cases, such as intranet proxy, catalog broker, etc.

Large Deviation Bounds for a Polling System with Two Queues and Multiple Servers

OpenAIRE

Wei, Fen

2004-01-01

In this paper, we present large deviation bounds for a discrete-time polling system consisting of two-par-allel queues and m servers. The arrival process in each queue is an arbitrary, and possibly correlated, stochastic process. Each server (serves) independently serves the two queues according to a Bernoulli service schedule. Using large deviation techniques, we analyze the tail behavior of the stationary distribution of the queue length processes, and derive upper and lower bounds of the b...

The Power of Heterogeneity: Parameter Relationships from Distributions

Science.gov (United States)

Röding, Magnus; Bradley, Siobhan J.; Williamson, Nathan H.; Dewi, Melissa R.; Nann, Thomas; Nydén, Magnus

2016-01-01

Complex scientific data is becoming the norm, many disciplines are growing immensely data-rich, and higher-dimensional measurements are performed to resolve complex relationships between parameters. Inherently multi-dimensional measurements can directly provide information on both the distributions of individual parameters and the relationships between them, such as in nuclear magnetic resonance and optical spectroscopy. However, when data originates from different measurements and comes in different forms, resolving parameter relationships is a matter of data analysis rather than experiment. We present a method for resolving relationships between parameters that are distributed individually and also correlated. In two case studies, we model the relationships between diameter and luminescence properties of quantum dots and the relationship between molecular weight and diffusion coefficient for polymers. Although it is expected that resolving complicated correlated relationships require inherently multi-dimensional measurements, our method constitutes a useful contribution to the modelling of quantitative relationships between correlated parameters and measurements. We emphasise the general applicability of the method in fields where heterogeneity and complex distributions of parameters are obstacles to scientific insight. PMID:27182701

Online Cloud Offloading Using Heterogeneous Enhanced Remote Radio Heads

KAUST Repository

Shnaiwer, Yousef N.

2018-02-12

This paper studies the cloud offloading gains of using heterogeneous enhanced remote radio heads (eRRHs) and dual-interface clients in fog radio access networks (F-RANs). First, the cloud offloading problem is formulated as a collection of independent sets selection problem over a network coding graph, and its NP-hardness is shown. Therefore, a computationally simple online heuristic algorithm is proposed, that maximizes cloud offloading by finding an efficient schedule of coded file transmissions from the eRRHs and the cloud base station (CBS). Furthermore, a lower bound on the average number of required CBS channels to serve all clients is derived. Simulation results show that our proposed framework that uses both network coding and a heterogeneous F-RAN setting enhances cloud offloading as compared to conventional homogeneous F-RANs with network coding.

A novel strategy to access high resolution DICOM medical images based on JPEG2000 interactive protocol

Science.gov (United States)

Tian, Yuan; Cai, Weihua; Sun, Jianyong; Zhang, Jianguo

2008-03-01

The demand for sharing medical information has kept rising. However, the transmission and displaying of high resolution medical images are limited if the network has a low transmission speed or the terminal devices have limited resources. In this paper, we present an approach based on JPEG2000 Interactive Protocol (JPIP) to browse high resolution medical images in an efficient way. We designed and implemented an interactive image communication system with client/server architecture and integrated it with Picture Archiving and Communication System (PACS). In our interactive image communication system, the JPIP server works as the middleware between clients and PACS servers. Both desktop clients and wireless mobile clients can browse high resolution images stored in PACS servers via accessing the JPIP server. The client can only make simple requests which identify the resolution, quality and region of interest and download selected portions of the JPEG2000 code-stream instead of downloading and decoding the entire code-stream. After receiving a request from a client, the JPIP server downloads the requested image from the PACS server and then responds the client by sending the appropriate code-stream. We also tested the performance of the JPIP server. The JPIP server runs stably and reliably under heavy load.

User-Friendly Data Servers for Climate Studies at the Asia-Pacific Data-Research Center (APDRC)

Science.gov (United States)

Yuan, G.; Shen, Y.; Zhang, Y.; Merrill, R.; Waseda, T.; Mitsudera, H.; Hacker, P.

2002-12-01

The APDRC was recently established within the International Pacific Research Center (IPRC) at the University of Hawaii. The APDRC mission is to increase understanding of climate variability in the Asia-Pacific region by developing the computational, data-management, and networking infrastructure necessary to make data resources readily accessible and usable by researchers, and by undertaking data-intensive research activities that will both advance knowledge and lead to improvements in data preparation and data products. A focus of recent activity is the implementation of user-friendly data servers. The APDRC is currently running a Live Access Server (LAS) developed at NOAA/PMEL to provide access to and visualization of gridded climate products via the web. The LAS also allows users to download the selected data subsets in various formats (such as binary, netCDF and ASCII). Most of the datasets served by the LAS are also served through our OPeNDAP server (formerly DODS), which allows users to directly access the data using their desktop client tools (e.g. GrADS, Matlab and Ferret). In addition, the APDRC is running an OPeNDAP Catalog/Aggregation Server (CAS) developed by Unidata at UCAR to serve climate data and products such as model output and satellite-derived products. These products are often large (> 2 GB) and are therefore stored as multiple files (stored separately in time or in parameters). The CAS remedies the inconvenience of multiple files and allows access to the whole dataset (or any subset that cuts across the multiple files) via a single request command from any DODS enabled client software. Once the aggregation of files is configured at the server (CAS), the process of aggregation is transparent to the user. The user only needs to know a single URL for the entire dataset, which is, in fact, stored as multiple files. CAS even allows aggregation of files on different systems and at different locations. Currently, the APDRC is serving NCEP, ECMWF

SmilesDrawer: Parsing and Drawing SMILES-Encoded Molecular Structures Using Client-Side JavaScript.

Science.gov (United States)

Probst, Daniel; Reymond, Jean-Louis

2018-01-22

Here we present SmilesDrawer, a dependency-free JavaScript component capable of both parsing and drawing SMILES-encoded molecular structures client-side, developed to be easily integrated into web projects and to display organic molecules in large numbers and fast succession. SmilesDrawer can draw structurally and stereochemically complex structures such as maitotoxin and C 60 without using templates, yet has an exceptionally small computational footprint and low memory usage without the requirement for loading images or any other form of client-server communication, making it easy to integrate even in secure (intranet, firewalled) or offline applications. These features allow the rendering of thousands of molecular structure drawings on a single web page within seconds on a wide range of hardware supporting modern browsers. The source code as well as the most recent build of SmilesDrawer is available on Github ( http://doc.gdb.tools/smilesDrawer/ ). Both yarn and npm packages are also available.

Breast dose in mammography is about 30% lower when realistic heterogeneous glandular distributions are considered

Energy Technology Data Exchange (ETDEWEB)

Hernandez, Andrew M., E-mail: amhern@ucdavis.edu [Biomedical Engineering Graduate Group, University of California Davis, Sacramento, California 95817 (United States); Seibert, J. Anthony; Boone, John M. [Departments of Radiology and Biomedical Engineering, Biomedical Engineering Graduate Group, University of California Davis, Sacramento, California 95817 (United States)

2015-11-15

Purpose: Current dosimetry methods in mammography assume that the breast is comprised of a homogeneous mixture of glandular and adipose tissues. Three-dimensional (3D) dedicated breast CT (bCT) data sets were used previously to assess the complex anatomical structure within the breast, characterizing the statistical distribution of glandular tissue in the breast. The purpose of this work was to investigate the effect of bCT-derived heterogeneous glandular distributions on dosimetry in mammography. Methods: bCT-derived breast diameters, volumes, and 3D fibroglandular distributions were used to design realistic compressed breast models comprised of heterogeneous distributions of glandular tissue. The bCT-derived glandular distributions were fit to biGaussian functions and used as probability density maps to assign the density distributions within compressed breast models. The MCNPX 2.6.0 Monte Carlo code was used to estimate monoenergetic normalized mean glandular dose “DgN(E)” values in mammography geometry. The DgN(E) values were then weighted by typical mammography x-ray spectra to determine polyenergetic DgN (pDgN) coefficients for heterogeneous (pDgN{sub hetero}) and homogeneous (pDgN{sub homo}) cases. The dependence of estimated pDgN values on phantom size, volumetric glandular fraction (VGF), x-ray technique factors, and location of the heterogeneous glandular distributions was investigated. Results: The pDgN{sub hetero} coefficients were on average 35.3% (SD, 4.1) and 24.2% (SD, 3.0) lower than the pDgN{sub homo} coefficients for the Mo–Mo and W–Rh x-ray spectra, respectively, across all phantom sizes and VGFs when the glandular distributions were centered within the breast phantom in the coronal plane. At constant breast size, increasing VGF from 7.3% to 19.1% lead to a reduction in pDgN{sub hetero} relative to pDgN{sub homo} of 23.6%–27.4% for a W–Rh spectrum. Displacement of the glandular distribution, at a distance equal to 10% of the

SmartMal: a service-oriented behavioral malware detection framework for mobile devices.

Science.gov (United States)

Wang, Chao; Wu, Zhizhong; Li, Xi; Zhou, Xuehai; Wang, Aili; Hung, Patrick C K

2014-01-01

This paper presents SmartMal--a novel service-oriented behavioral malware detection framework for vehicular and mobile devices. The highlight of SmartMal is to introduce service-oriented architecture (SOA) concepts and behavior analysis into the malware detection paradigms. The proposed framework relies on client-server architecture, the client continuously extracts various features and transfers them to the server, and the server's main task is to detect anomalies using state-of-art detection algorithms. Multiple distributed servers simultaneously analyze the feature vector using various detectors and information fusion is used to concatenate the results of detectors. We also propose a cycle-based statistical approach for mobile device anomaly detection. We accomplish this by analyzing the users' regular usage patterns. Empirical results suggest that the proposed framework and novel anomaly detection algorithm are highly effective in detecting malware on Android devices.

Mastering Windows Server 2008 Networking Foundations

CERN Document Server

Minasi, Mark; Mueller, John Paul

2011-01-01

Find in-depth coverage of general networking concepts and basic instruction on Windows Server 2008 installation and management including active directory, DNS, Windows storage, and TCP/IP and IPv4 networking basics in Mastering Windows Server 2008 Networking Foundations. One of three new books by best-selling author Mark Minasi, this guide explains what servers do, how basic networking works (IP basics and DNS/WINS basics), and the fundamentals of the under-the-hood technologies that support staff must understand. Learn how to install Windows Server 2008 and build a simple network, security co

National Medical Terminology Server in Korea

Science.gov (United States)

Lee, Sungin; Song, Seung-Jae; Koh, Soonjeong; Lee, Soo Kyoung; Kim, Hong-Gee

Interoperable EHR (Electronic Health Record) necessitates at least the use of standardized medical terminologies. This paper describes a medical terminology server, LexCare Suite, which houses terminology management applications, such as a terminology editor, and a terminology repository populated with international standard terminology systems such as Systematized Nomenclature of Medicine (SNOMED). The server is to satisfy the needs of quality terminology systems to local primary to tertiary hospitals. Our partner general hospitals have used the server to test its applicability. This paper describes the server and the results of the applicability test.

Upgrading a TCABR Data Analysis and Acquisition System for Remote Participation Using Java, XML, RCP and Modern Client/Server Communication/Authentication

Energy Technology Data Exchange (ETDEWEB)

De Sa, W. [University of Sao Paulo - Institute of Physics - Plasma Physics Laboratory, Sao Paulo (Brazil)

2009-07-01

Each plasma physics laboratory has a proprietary scheme to control and data acquisition system. Usually, it is different from one laboratory to another. It means that each laboratory has its own way of control the experiment and retrieving data from the database. Fusion research relies to a great extent on international collaboration and it is difficult to follow the work remotely with private system. The TCABR data analysis and acquisition system has been upgraded to support a joint research programme using remote participation technologies. The architecture of the new system uses Java language as programming environment. Since application parameters and hardware in a joint experiment are very complex and with a large variability of components, requirement and specification solutions need to be flexible and modular, independent from operating system and computers architecture. To describe and to organize the information on all the components and the connections among them, systems are developed using the extensible Markup Language (XML) technology. The communication between clients and servers use Remote Procedure Call (RPC) based on the XML (RPC-XML technology). The integration among Java language, XML and RPC-XML technologies allows developing easily a standard data and communication access layer between users and laboratories using common software libraries and Web application. The libraries allow data retrieval using the same methods for all user laboratories in the joint collaboration and the Web application allows a simple Graphical User Interface (GUI) access. TCABR tokamak team collaborating with the CFN (Nuclear Fusion Center, Technical University of Lisbon) are implementing this Remote Participation technologies that are going to be tested at the Joint Experiment on TCABR (TCABR-JE), a Host Laboratory Experiment, organized in cooperation with the IAEA (International Atomic Energy Agency) in the framework of the IAEA Coordinated Research Project (CRP) on

REPLIKASI UNIDIRECTIONAL PADA HETEROGEN DATABASE

OpenAIRE

Hendro Nindito; Evaristus Didik Madyatmadja; Albert Verasius Dian Sano

2013-01-01

The use of diverse database technology in enterprise today can not be avoided. Thus, technology is needed to generate information in real time. The purpose of this research is to discuss a database replication technology that can be applied in heterogeneous database environments. In this study we use Windows-based MS SQL Server database to Linux-based Oracle database as the goal. The research method used is prototyping where development can be done quickly and testing of working models of the...

A Survey on Smartphone-Based Crowdsensing Solutions

Directory of Open Access Journals (Sweden)

Willian Zamora

2016-01-01

Full Text Available In recent years, the widespread adoption of mobile phones, combined with the ever-increasing number of sensors that smartphones are equipped with, greatly simplified the generalized adoption of crowdsensing solutions by reducing hardware requirements and costs to a minimum. These factors have led to an outstanding growth of crowdsensing proposals from both academia and industry. In this paper, we provide a survey of smartphone-based crowdsensing solutions that have emerged in the past few years, focusing on 64 works published in top-ranked journals and conferences. To properly analyze these previous works, we first define a reference framework based on how we classify the different proposals under study. The results of our survey evidence that there is still much heterogeneity in terms of technologies adopted and deployment approaches, although modular designs at both client and server elements seem to be dominant. Also, the preferred client platform is Android, while server platforms are typically web-based, and client-server communications mostly rely on XML or JSON over HTTP. The main detected pitfall concerns the performance evaluation of the different proposals, which typically fail to make a scalability analysis despite being critical issue when targeting very large communities of users.

A distributed computing model for telemetry data processing

Science.gov (United States)

Barry, Matthew R.; Scott, Kevin L.; Weismuller, Steven P.

1994-05-01

We present a new approach to distributing processed telemetry data among spacecraft flight controllers within the control centers at NASA's Johnson Space Center. This approach facilitates the development of application programs which integrate spacecraft-telemetered data and ground-based synthesized data, then distributes this information to flight controllers for analysis and decision-making. The new approach combines various distributed computing models into one hybrid distributed computing model. The model employs both client-server and peer-to-peer distributed computing models cooperating to provide users with information throughout a diverse operations environment. Specifically, it provides an attractive foundation upon which we are building critical real-time monitoring and control applications, while simultaneously lending itself to peripheral applications in playback operations, mission preparations, flight controller training, and program development and verification. We have realized the hybrid distributed computing model through an information sharing protocol. We shall describe the motivations that inspired us to create this protocol, along with a brief conceptual description of the distributed computing models it employs. We describe the protocol design in more detail, discussing many of the program design considerations and techniques we have adopted. Finally, we describe how this model is especially suitable for supporting the implementation of distributed expert system applications.

A distributed computing model for telemetry data processing

Science.gov (United States)

Barry, Matthew R.; Scott, Kevin L.; Weismuller, Steven P.

1994-01-01

We present a new approach to distributing processed telemetry data among spacecraft flight controllers within the control centers at NASA's Johnson Space Center. This approach facilitates the development of application programs which integrate spacecraft-telemetered data and ground-based synthesized data, then distributes this information to flight controllers for analysis and decision-making. The new approach combines various distributed computing models into one hybrid distributed computing model. The model employs both client-server and peer-to-peer distributed computing models cooperating to provide users with information throughout a diverse operations environment. Specifically, it provides an attractive foundation upon which we are building critical real-time monitoring and control applications, while simultaneously lending itself to peripheral applications in playback operations, mission preparations, flight controller training, and program development and verification. We have realized the hybrid distributed computing model through an information sharing protocol. We shall describe the motivations that inspired us to create this protocol, along with a brief conceptual description of the distributed computing models it employs. We describe the protocol design in more detail, discussing many of the program design considerations and techniques we have adopted. Finally, we describe how this model is especially suitable for supporting the implementation of distributed expert system applications.

SSWAP: A Simple Semantic Web Architecture and Protocol for semantic web services.

Science.gov (United States)

Gessler, Damian D G; Schiltz, Gary S; May, Greg D; Avraham, Shulamit; Town, Christopher D; Grant, David; Nelson, Rex T

2009-09-23

SSWAP (Simple Semantic Web Architecture and Protocol; pronounced "swap") is an architecture, protocol, and platform for using reasoning to semantically integrate heterogeneous disparate data and services on the web. SSWAP was developed as a hybrid semantic web services technology to overcome limitations found in both pure web service technologies and pure semantic web technologies. There are currently over 2400 resources published in SSWAP. Approximately two dozen are custom-written services for QTL (Quantitative Trait Loci) and mapping data for legumes and grasses (grains). The remaining are wrappers to Nucleic Acids Research Database and Web Server entries. As an architecture, SSWAP establishes how clients (users of data, services, and ontologies), providers (suppliers of data, services, and ontologies), and discovery servers (semantic search engines) interact to allow for the description, querying, discovery, invocation, and response of semantic web services. As a protocol, SSWAP provides the vocabulary and semantics to allow clients, providers, and discovery servers to engage in semantic web services. The protocol is based on the W3C-sanctioned first-order description logic language OWL DL. As an open source platform, a discovery server running at http://sswap.info (as in to "swap info") uses the description logic reasoner Pellet to integrate semantic resources. The platform hosts an interactive guide to the protocol at http://sswap.info/protocol.jsp, developer tools at http://sswap.info/developer.jsp, and a portal to third-party ontologies at http://sswapmeet.sswap.info (a "swap meet"). SSWAP addresses the three basic requirements of a semantic web services architecture (i.e., a common syntax, shared semantic, and semantic discovery) while addressing three technology limitations common in distributed service systems: i.e., i) the fatal mutability of traditional interfaces, ii) the rigidity and fragility of static subsumption hierarchies, and iii) the

Federal Emergency Management Information System (FEMIS) Data Management Guide for FEMIS Version 1.4.6

Energy Technology Data Exchange (ETDEWEB)

Angel, L.K.; Bower, J.C.; Burnett, R.A.; Downing, T.R.; Fangman, P.M.; Hoza, M.; Johnson, D.M.; Johnson, S.M.; Loveall, R.M.; Millard, W.D.; Schulze, S.A.; Wood, B.M.

1999-06-29

The Federal Emergency Management Information System (FEMIS) is an emergency management planning and response tool that was developed by the Pacific Northwest National Laboratory (PNNL) under the direction of the U.S. Army Chemical Biological Defense Command. The FEMIS System Administration Guide provides information necessary for the system administrator to maintain the FEMIS system. The FEMIS system is designed for a single Chemical Stockpile Emergency Preparedness Program (CSEPP) site that has multiple Emergency Operations Centers (EOCs). Each EOC has personal computers (PCs) that emergency planners and operations personnel use to do their jobs. These PCs are corrected via a local area network (LAN) to servers that provide EOC-wide services. Each EOC is interconnected to other EOCs via a Wide Area Network (WAN). Thus, FEMIS is an integrated software product that resides on client/server computer architecture. The main body of FEMIS software, referred to as the FEMIS Application Software, resides on the PC client(s) and is directly accessible to emergency management personnel. The remainder of the FEMIS software, referred to as the FEMIS Support Software, resides on the UNIX server. The Support Software provides the communication data distribution and notification functionality necessary to operate FEMIS in a networked, client/server environment.

Federal Emergency Management Information System (FEMIS) System Administration Guide for FEMIS Version 1.4.6

Energy Technology Data Exchange (ETDEWEB)

Arp, J.A.; Bower, J.C.; Burnett, R.A.; Carter, R.J.; Downing, T.R.; Fangman, P.M.; Gerhardstein, L.H.; Homer, B.J.; Johnson, D.M.; Johnson, R.L.; Johnson, S.M.; Loveall, R.M.; Martin, T.J.; Millard, W.D.; Schulze, S.A.; Stoops, L.R.; Tzemos, S.; Wood, B.M.

1999-06-29

The Federal Emergency Management Information System (FEMIS) is an emergency management planning and response tool that was developed by the Pacific Northwest National Laboratory (PNNL) under the direction of the U.S. Army Chemical Biological Defense Command. The FEMIS System Administration Guide provides information necessary for the system administrator to maintain the FEMIS system. The FEMIS system is designed for a single Chemical Stockpile Emergency Preparedness Program (CSEPP) site that has multiple Emergency Operations Centers (EOCs). Each EOC has personal computers (PCs) that emergency planners and operations personnel use to do their jobs. These PCs are corrected via a local area network (LAN) to servers that provide EOC-wide services. Each EOC is interconnected to other EOCs via a Wide Area Network (WAN). Thus, FEMIS is an integrated software product that resides on client/server computer architecture. The main body of FEMIS software, referred to as the FEMIS Application Software, resides on the PC client(s) and is directly accessible to emergency management personnel. The remainder of the FEMIS software, referred to as the FEMIS Support Software, resides on the UNIX server. The Support Software provides the communication data distribution and notification functionality necessary to operate FEMIS in a networked, client/server environment.

The Effects of Client-Counselor Racial Matching on Therapeutic Outcome

Science.gov (United States)

Kim, Eunha; Kang, Minchul

2018-01-01

This study explored the effects of ethnic/racial matching on psychotherapy outcomes via the number of counseling sessions attended by clients, using clinical data collected from a university's counseling center. A total sample of 644 clients (193 men, 448 women) was selected and the ethnic/racial distribution of the sample comprised 499…

Calculation of breaking radiation dose fields in heterogenous media by a method of the transformation of axial distribution

International Nuclear Information System (INIS)

Mil'shtejn, R.S.

1988-01-01

Analysis of dose fields in a heterogeneous tissue equivalent medium has shown that dose distributions have radial symmetry and can be described by a curve of axial distribution with renormalization of maximum ionization depth. A method of the calculation of a dose field in a heterogeneous medium using the principle of radial symmetry is presented

Online Cloud Offloading Using Heterogeneous Enhanced Remote Radio Heads

KAUST Repository

Shnaiwer, Yousef N.; Sorour, Sameh; Sadeghi, Parastoo; Al-Naffouri, Tareq Y.